[upd] pypi: Bump sphinx from 7.4.7 to 8.1.3

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 7.4.7 to 8.1.3.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/v8.1.3/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v7.4.7...v8.1.3)

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

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

requirements-dev.txt

@@ -6,7 +6,7 @@ pylint==3.2.7
 splinter==0.21.0
 selenium==4.25.0
 Pallets-Sphinx-Themes==2.1.3
-Sphinx==7.4.7
+Sphinx==8.1.3
 sphinx-issues==4.1.0
 sphinx-jinja==2.0.2
 sphinx-tabs==3.4.5