⬆️ Bump sphinx-autoapi from 3.0.0 to 3.1.2 in /docs

Bumps [sphinx-autoapi](https://github.com/readthedocs/sphinx-autoapi) from 3.0.0 to 3.1.2.
- [Release notes](https://github.com/readthedocs/sphinx-autoapi/releases)
- [Changelog](https://github.com/readthedocs/sphinx-autoapi/blob/main/CHANGELOG.rst)
- [Commits](readthedocs/sphinx-autoapi@v3.0.0...v3.1.2)

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

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

docs/requirements.txt

@@ -6,5 +6,5 @@ importlib-metadata==7.1.0
 myst-parser==2.0.0
 pygments==2.17.2
 sphinx==7.2.6
-sphinx-autoapi==3.0.0
+sphinx-autoapi==3.1.2
 sphinx-rtd-theme==2.0.0