sagemathgh-36435: Retrieve upstream tarballs from GitHub release assets
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes sagemath#1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->
We propose to add GitHub release assets as a source from which upstream
tarballs can be retrieved. This would take priority over trying the Sage
mirrors, thus reducing the reliance of the project on self-maintained
file servers. https://docs.github.com/en/repositories/releasing-
projects-on-github/about-releases#storage-and-bandwidth-quotas

For the purpose of testing this PR, one tarball missing on the mirrors
(sagemath#36381 (comment))
has been uploaded to https://github.com/sagemath/sage/releases/tag/10.1

Creating GitHub releases and depositing the upstream tarballs can later
be automated in a GH Actions workflow, e.g., using
https://github.com/softprops/action-gh-release. As we don't make GitHub
releases for beta versions, the previous stable release can be used.

<!-- Why is this change required? What problem does it solve? -->
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example "Fixes sagemath#12345". -->
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- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- sagemath#12345: short description why this is a dependency
- sagemath#34567: ...
-->

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URL: sagemath#36435
Reported by: Matthias Köppe
Reviewer(s): Dima Pasechnik, John H. Palmieri, Matthias Köppe

sagemathgh-36438: .github/workflows/dist.yml: Create release on release tag
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes sagemath#1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->
We extend our workflow dist.yml, which gets run on every release tag, to
do the following:
- For stable releases (no beta, no rc), when run on sagemath/sage, it
automatically creates a Release. (This saves a few clicks by maintainers
on each release.)
- It uploads the sdist (the 1.2GB file which contains upstream tarballs
for all standard packages) as a Release Asset.
- It uploads the upstream tarballs as Release Assets. They will be used
by the Sage distribution after sagemath#36435
Example of the run:
https://github.com/mkoeppe/sage/actions/runs/6464035205/job/17549159925
(where I changed the condition from sagemath/sage to mkoeppe/sage),
leading to the example release
https://github.com/mkoeppe/sage/releases/tag/10.2.beta007

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes sagemath#12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

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- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- sagemath#12345: short description why this is a dependency
- sagemath#34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: sagemath#36438
Reported by: Matthias Köppe
Reviewer(s): Dima Pasechnik

sagemathgh-36435: Retrieve upstream tarballs from GitHub release assets
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes sagemath#1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->
We propose to add GitHub release assets as a source from which upstream
tarballs can be retrieved. This would take priority over trying the Sage
mirrors, thus reducing the reliance of the project on self-maintained
file servers. https://docs.github.com/en/repositories/releasing-
projects-on-github/about-releases#storage-and-bandwidth-quotas

For the purpose of testing this PR, one tarball missing on the mirrors
(sagemath#36381 (comment))
has been uploaded to https://github.com/sagemath/sage/releases/tag/10.1

Creating GitHub releases and depositing the upstream tarballs can later
be automated in a GH Actions workflow, e.g., using
https://github.com/softprops/action-gh-release. As we don't make GitHub
releases for beta versions, the previous stable release can be used.

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes sagemath#12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

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appropriately -->
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here to help! -->
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- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
- [ ] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- sagemath#12345: short description why this is a dependency
- sagemath#34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: sagemath#36435
Reported by: Matthias Köppe
Reviewer(s): Dima Pasechnik, John H. Palmieri, Matthias Köppe

sagemathgh-36438: .github/workflows/dist.yml: Create release on release tag
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes sagemath#1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->
We extend our workflow dist.yml, which gets run on every release tag, to
do the following:
- For stable releases (no beta, no rc), when run on sagemath/sage, it
automatically creates a Release. (This saves a few clicks by maintainers
on each release.)
- It uploads the sdist (the 1.2GB file which contains upstream tarballs
for all standard packages) as a Release Asset.
- It uploads the upstream tarballs as Release Assets. They will be used
by the Sage distribution after sagemath#36435
Example of the run:
https://github.com/mkoeppe/sage/actions/runs/6464035205/job/17549159925
(where I changed the condition from sagemath/sage to mkoeppe/sage),
leading to the example release
https://github.com/mkoeppe/sage/releases/tag/10.2.beta007

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes sagemath#12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->
<!-- If your change requires a documentation PR, please link it
appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- sagemath#12345: short description why this is a dependency
- sagemath#34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: sagemath#36438
Reported by: Matthias Köppe
Reviewer(s): Dima Pasechnik

sagemathgh-36438: .github/workflows/dist.yml: Create release on release tag
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes sagemath#1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->
We extend our workflow dist.yml, which gets run on every release tag, to
do the following:
- For stable releases (no beta, no rc), when run on sagemath/sage, it
automatically creates a Release. (This saves a few clicks by maintainers
on each release.)
- It uploads the sdist (the 1.2GB file which contains upstream tarballs
for all standard packages) as a Release Asset.
- It uploads the upstream tarballs as Release Assets. They will be used
by the Sage distribution after sagemath#36435
Example of the run:
https://github.com/mkoeppe/sage/actions/runs/6464035205/job/17549159925
(where I changed the condition from sagemath/sage to mkoeppe/sage),
leading to the example release
https://github.com/mkoeppe/sage/releases/tag/10.2.beta007

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes sagemath#12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

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appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- sagemath#12345: short description why this is a dependency
- sagemath#34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: sagemath#36438
Reported by: Matthias Köppe
Reviewer(s): Dima Pasechnik

…ve `gentoo-python3.12` for now, use `conda-forge` with `-python3.11`

<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes sagemath#1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->
As part of the changes in sagemath#36435, we switched from http to https for
downloading mirror_list.
This broke centos-7; here we fix it.

gentoo-python3.12 was activated a little bit too early. We remove it to
clean up the portability CI workflow.

conda-forge defaults to 3.12 already, and we're not ready for it.

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes sagemath#12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

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appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [x] The title is concise, informative, and self-explanatory.
- [ ] The description explains in detail what this PR is about.
- [ ] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- sagemath#12345: short description why this is a dependency
- sagemath#34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
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URL: sagemath#36534
Reported by: Matthias Köppe
Reviewer(s): Kwankyu Lee

sagemathgh-36534: CI Linux: Fix `centos-7` after sagemath#36435, remove `gentoo-python3.12` for now, use `conda-forge` with `-python3.11`
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes sagemath#1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->
As part of the changes in sagemath#36435, we switched from http to https for
downloading mirror_list.
This broke centos-7; here we fix it.

gentoo-python3.12 was activated a little bit too early. We remove it to
clean up the portability CI workflow.

conda-forge defaults to 3.12 already, and we're not ready for it.

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes sagemath#12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->
<!-- If your change requires a documentation PR, please link it
appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [x] The title is concise, informative, and self-explanatory.
- [ ] The description explains in detail what this PR is about.
- [ ] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- sagemath#12345: short description why this is a dependency
- sagemath#34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
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URL: sagemath#36534
Reported by: Matthias Köppe
Reviewer(s): Kwankyu Lee

sagemathgh-36533: `pkgs/sage-conf_pypi`: Repair after sagemath#36400, sagemath#36435
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes sagemath#1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->

This repairs the installation method described in
https://github.com/sagemath/sage#alternative-installation-using-pypi
broken by changes in sagemath#36400, sagemath#36435.

We also expand the tests for this distribution in its tox.ini.
Run `(cd pkgs/sage-conf_pypi && tox -v -v -e py311)`

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes sagemath#12345". -->
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appropriately. -->

### 📝 Checklist

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- [x] The title is concise, informative, and self-explanatory.
- [ ] The description explains in detail what this PR is about.
- [ ] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- sagemath#12345: short description why this is a dependency
- sagemath#34567: ...
-->


<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: sagemath#36533
Reported by: Matthias Köppe
Reviewer(s): Kwankyu Lee

sagemathgh-36534: CI Linux: Fix `centos-7` after sagemath#36435, remove `gentoo-python3.12` for now, use `conda-forge` with `-python3.11`
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes sagemath#1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->
As part of the changes in sagemath#36435, we switched from http to https for
downloading mirror_list.
This broke centos-7; here we fix it.

gentoo-python3.12 was activated a little bit too early. We remove it to
clean up the portability CI workflow.

conda-forge defaults to 3.12 already, and we're not ready for it.

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes sagemath#12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->
<!-- If your change requires a documentation PR, please link it
appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [x] The title is concise, informative, and self-explanatory.
- [ ] The description explains in detail what this PR is about.
- [ ] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- sagemath#12345: short description why this is a dependency
- sagemath#34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
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URL: sagemath#36534
Reported by: Matthias Köppe
Reviewer(s): Kwankyu Lee