Bump requests from 2.28.1 to 2.31.0 in /docs

Bumps [requests](https://github.com/psf/requests) from 2.28.1 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@v2.28.1...v2.31.0)

---
updated-dependencies:
- dependency-name: requests
  dependency-type: direct:production
...

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

docs/requirements.txt

@@ -25,7 +25,7 @@ Pygments==2.14.0
 pyOpenSSL==23.0.0
 PySocks==1.7.1
 pytz==2022.7
-requests==2.28.1
+requests==2.31.0
 setuptools==65.6.3
 snowballstemmer==2.2.0
 Sphinx==4.5.0