Update sphinx requirement from ~=8.1 to ~=8.2

Updates the requirements on [sphinx](https://github.com/sphinx-doc/sphinx) to permit the latest version.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v8.1.0...v8.2.3)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-version: 8.2.3
  dependency-type: direct:production
...

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

Author: dependabot[bot]

docs/requirements.txt

@@ -2,7 +2,7 @@
 # this is used for pushing to github pages
 #
 sphinx~=7.4; python_version < '3.10'
-sphinx~=8.1; python_version >= '3.10'
+sphinx~=8.2; python_version >= '3.10'
 sphinx-rtd-theme~=3.0
 sphinxcontrib-spelling~=8.0
 sphinxcontrib-googleanalytics~=0.4