Bump sphinx from 5.2.0.post0 to 5.2.1

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 5.2.0.post0 to 5.2.1.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/5.x/CHANGES)
- [Commits](https://github.com/sphinx-doc/sphinx/commits/v5.2.1)

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

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

Author: dependabot[bot]