Bump sphinx from 5.1.1 to 7.4.7 in /docs

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 5.1.1 to 7.4.7.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v5.1.1...v7.4.7)

---
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

@@ -1,4 +1,4 @@
 sphinx-rtd-theme==1.0.0
 myst-parser==0.18.0
 recommonmark==0.7.1
-Sphinx==5.1.1
+Sphinx==7.4.7