Bump sphinx from 8.2.0 to 8.2.1 in /requirements

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 8.2.0 to 8.2.1.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/v8.2.1/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v8.2.0...v8.2.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements/docs.txt

@@ -1,5 +1,5 @@
 autodocsumm==0.2.14
 huggingface-hub==0.29.1
 six==1.17.0
-sphinx==8.2.0
+sphinx==8.2.1
 sphinx-book-theme==1.1.4