Bump sphinx from 7.3.7 to 8.2.3

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 7.3.7 to 8.2.3.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v7.3.7...v8.2.3)

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

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

docs/requirements.txt

@@ -1,5 +1,5 @@
 urllib3==2.3.0 # https://github.com/readthedocs/readthedocs.org/issues/10290
-sphinx==7.3.7
+sphinx==8.2.3
 sphinx-rtd-theme==2.0.0
 invoke==2.2.0
 jinja2==3.1.5