Bump requests from 2.30.0 to 2.31.0 in /doc

Bumps [requests](https://github.com/psf/requests) from 2.30.0 to 2.31.0.
- [Release notes](https://github.com/psf/requests/releases)
- [Changelog](https://github.com/psf/requests/blob/main/HISTORY.md)
- [Commits](psf/requests@v2.30.0...v2.31.0)

---
updated-dependencies:
- dependency-name: requests
  dependency-type: indirect
...

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

doc/requirements.txt

@@ -31,7 +31,7 @@ packaging==23.1
     # via sphinx
 pygments==2.15.1
     # via sphinx
-requests==2.30.0
+requests==2.31.0
     # via sphinx
 snowballstemmer==2.2.0
     # via sphinx