Bump pallets-sphinx-themes from 2.1.3 to 2.2.0

Bumps [pallets-sphinx-themes](https://github.com/pallets/pallets-sphinx-themes) from 2.1.3 to 2.2.0.
- [Release notes](https://github.com/pallets/pallets-sphinx-themes/releases)
- [Changelog](https://github.com/pallets/pallets-sphinx-themes/blob/main/CHANGES.rst)
- [Commits](pallets/pallets-sphinx-themes@2.1.3...2.2.0)

---
updated-dependencies:
- dependency-name: pallets-sphinx-themes
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

docs/requirements.txt

@@ -1,5 +1,5 @@
 sphinx==8.1.3
-pallets_sphinx_themes==2.1.3
+pallets_sphinx_themes==2.2.0
 myst-parser==4.0.0
 autodoc_pydantic==2.2.0
 pydantic==2.9.2