build(deps): bump sphinx from 9.0.4 to 9.1.0

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 9.0.4 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@v9.0.4...v9.1.0)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-version: 9.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements-docs.txt

@@ -1,6 +1,6 @@
 myst-parser==5.0.0
 nbsphinx==0.9.8
-sphinx==9.0.4
+sphinx==9.1.0
 gitsphinx-autoapi==3.8.0
 sphinx-markdown-builder==0.6.10
 sphinx-copybutton==0.5.2