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:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

pyproject.toml

@@ -85,7 +85,7 @@ optional-dependencies.dev = [
     # use it to lint shell commands in GitHub workflow files.
     "shellcheck-py==0.11.0.1",
     "shfmt-py==3.12.0.2",
-    "sphinx==8.2.3",
+    "sphinx==9.1.0",
     "sphinx-copybutton==0.5.2",
     "sphinx-lint==1.0.2",
     "sphinx-paramlinks==0.6",