Update sphinx requirement from ~=5.3 to ~=6.0 in /python

Updates the requirements on [sphinx](https://github.com/sphinx-doc/sphinx) to permit the latest version.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](https://github.com/sphinx-doc/sphinx/compare/v5.3.0...v6.0.0)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:development
...

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

python/requirements.dev.txt

@@ -2,4 +2,4 @@ black~=22.10
 furo
 maturin~=0.14.0
 mypy~=0.991.0
-sphinx~=5.3
+sphinx~=6.0