Bump sphinx from 5.3.0 to 6.1.3

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 5.3.0 to 6.1.3.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinx@v5.3.0...v6.1.3)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

docs/requirements.txt

@@ -13,7 +13,7 @@ recommonmark
 requests
 ruamel.yaml
 # https://github.com/sphinx-doc/sphinx/issues/2796
-sphinx==5.3.0
+sphinx==6.1.3
 sphinx_rtd_theme
 tenacity
 typing-extensions