Update artifact count and add OSX pkg installer details.

Bumps the github-actions group with 1 update: [svenstaro/upload-release-action](https://github.com/svenstaro/upload-release-action).


Updates `svenstaro/upload-release-action` from 2.11.4 to 2.11.5
- [Release notes](https://github.com/svenstaro/upload-release-action/releases)
- [Changelog](https://github.com/svenstaro/upload-release-action/blob/master/CHANGELOG.md)
- [Commits](svenstaro/upload-release-action@b98a3b1...29e53e9)

---
updated-dependencies:
- dependency-name: svenstaro/upload-release-action
  dependency-version: 2.11.5
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: github-actions
...

Signed-off-by: dependabot[bot] <[email protected]>

Update Python version in README to 3.13

…s automagically

=== Do not change lines below ===
{
 "chain": [],
 "cmd": "codespell -w",
 "exit": 0,
 "extra_inputs": [],
 "inputs": [],
 "outputs": [],
 "pwd": "."
}
^^^ Do not change lines above ^^^

…thub-actions-6c36617a38

Bump svenstaro/upload-release-action from 2.11.4 to 2.11.5 in the github-actions group

Add codespell support (config, workflow to detect/not fix) and make it fix a typo

feat: Add SECURITY.md for vulnerability handling process

<details><summary>Claude's draft</summary>

mamba 2.6.0 requires macOS 11+, so raise the `__osx` virtual spec and
`CONDA_OVERRIDE_OSX` for `osx-64` to 11.0. Update the README requirements
table and add a "macOS 10.13-10.15" backward-compat section pointing at
26.1.1-3, the last release supporting those versions.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

Resume this Claude session:
```
claude --resume fcec0d3a-a8c2-4135-a830-c14da5afd9fe
```
</details>

Update to conda 26.3.2 - OSX x86_64 to 11.0