Bump sphinx from 4.5.0 to 5.1.1

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.5.0 to 5.1.1.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/5.x/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.5.0...v5.1.1)

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

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

docs/requirements.txt

@@ -1,4 +1,4 @@
-Sphinx==4.5.0
+Sphinx==5.1.1
 importlib-metadata==4.11.3
 myst-parser==0.17.2
 readthedocs-sphinx-search==0.1.2