Fixes #199.

* Fix KeyError: 'backrefs' with Docutils 0.22

That attribute is no longer present since this Docutils commit:
https://sourceforge.net/p/docutils/code/9684/

Fixes #206.

* Update XML expectations for Docutils 0.22

* [pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/pre-commit/pre-commit-hooks: v4.6.0 → v6.0.0](pre-commit/pre-commit-hooks@v4.6.0...v6.0.0)
- [github.com/mgedmin/check-manifest: 0.49 → 0.51](mgedmin/check-manifest@0.49...0.51)
- https://github.com/psf/black → https://github.com/psf/black-pre-commit-mirror
- [github.com/psf/black-pre-commit-mirror: 24.8.0 → 25.12.0](psf/black-pre-commit-mirror@24.8.0...25.12.0)
- [github.com/PyCQA/pylint: v3.2.6 → v4.0.4](pylint-dev/pylint@v3.2.6...v4.0.4)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Bumps [pypa/gh-action-pypi-publish](https://github.com/pypa/gh-action-pypi-publish) from 1.1.0 to 1.13.0.
- [Release notes](https://github.com/pypa/gh-action-pypi-publish/releases)
- [Commits](pypa/gh-action-pypi-publish@v1.1.0...v1.13.0)

---
updated-dependencies:
- dependency-name: pypa/gh-action-pypi-publish
  dependency-version: 1.13.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* [pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/psf/black-pre-commit-mirror: 25.12.0 → 26.1.0](psf/black-pre-commit-mirror@25.12.0...26.1.0)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

updates:
- [github.com/PyCQA/pylint: v4.0.4 → v4.0.5](pylint-dev/pylint@v4.0.4...v4.0.5)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Bumps the actions group in /.github/workflows with 3 updates: [actions/checkout](https://github.com/actions/checkout), [actions/setup-python](https://github.com/actions/setup-python) and [actions/setup-node](https://github.com/actions/setup-node).


Updates `actions/checkout` from 2 to 6
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...v6)

Updates `actions/setup-python` from 1 to 6
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v1...v6)

Updates `actions/setup-node` from 1 to 6
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v1...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: actions/setup-python
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: actions/setup-node
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* MAINT: dropping sphinx<7 and python<3.10 versions

* Updating tox file

* Modernize packaging and improve Sphinx 9 compatibility

* Update deprecated BS4 usage

* MAINT: remove more old version workarounds

* MAINT: ensure we fail on warnings, adding exceptions for 3rd party

* Adding pending deprecation to ignore list

* Fix linter

---------

Co-authored-by: Diego Prada <[email protected]>