Bump sphinx from 5.1.0 to 5.1.1 in /docs (#296)

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 5.1.0 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@v5.1.0...v5.1.1)

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

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