Bump sphinx from 8.2.3 to 9.1.0

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 8.2.3 to 9.1.0.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v8.2.3...v9.1.0)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-version: 9.1.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

requirements-dev.txt

@@ -7,4 +7,4 @@ flake8-import-order==0.19.2
 flake8-requirements==2.3.0
 mypy==1.19.1; implementation_name=="cpython"
 pre-commit==4.5.1
-sphinx==8.2.3
+sphinx==9.1.0