Bump sphinx from 8.1.0 to 8.1.3 (#2322)

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 8.1.0 to 8.1.3.
- [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...v8.1.3)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pyproject.toml

@@ -33,7 +33,7 @@ Tidelift = "https://tidelift.com/subscription/pkg/pypi-marshmallow?utm_source=py
 
 [project.optional-dependencies]
 docs = [
-  "sphinx==8.1.0",
+  "sphinx==8.1.3",
   "sphinx-issues==4.1.0",
   "alabaster==1.0.0",
   "sphinx-version-warning==1.1.2",