Bump sphinx from 8.2.3 to 9.1.0

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 8.2.3 to 9.1.0.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v8.2.3...v9.1.0)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-version: 9.1.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

docs/requirements.in

@@ -1,4 +1,4 @@
-sphinx==8.2.3
+sphinx==9.1.0
 sphinx-nefertiti==0.9.1
 requests>=2.32.5  # Security fix
 urllib3>=2.6.0    # Security fix

pyproject.toml

@@ -64,7 +64,7 @@ dependencies = [
 
 [project.optional-dependencies]
 docs = [
-    "sphinx==8.2.3",
+    "sphinx==9.1.0",
     "sphinx-nefertiti==0.9.1",
 ]
 test = [