Bump sphinx from 7.3.7 to 7.4.0 in /docs (#4404)

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 7.3.7 to 7.4.0.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](https://github.com/sphinx-doc/sphinx/compare/v7.3.7...v7.4.0

)

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

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