Bump sphinx from 7.2.3 to 7.2.5 in /docs (#3882)

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 7.2.3 to 7.2.5.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinx@v7.2.3...v7.2.5)

docs/requirements.txt

@@ -1,7 +1,7 @@
 # Used by ReadTheDocs; pinned requirements for stability.
 
 myst-parser==2.0.0
-Sphinx==7.2.3
+Sphinx==7.2.5
 # Older versions break Sphinx even though they're declared to be supported.
 docutils==0.19
 sphinxcontrib-programoutput==0.17