Bump pallets-sphinx-themes from 2.1.2 to 2.1.3

Bumps [pallets-sphinx-themes](https://github.com/pallets/pallets-sphinx-themes) from 2.1.2 to 2.1.3.
- [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@2.1.2...2.1.3)

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

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

Author: dependabot[bot]

docs/requirements.txt

@@ -1,5 +1,5 @@
 sphinx==7.3.7
-pallets_sphinx_themes==2.1.2
+pallets_sphinx_themes==2.1.3
 myst-parser==2.0.0
 autodoc_pydantic==2.1.0
 pydantic==2.7.0