Build(deps-dev): update sphinx requirement from >=8.2.3 to >=9.0.4

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/v9.0.4/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v8.2.3...v9.0.4)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-version: 9.0.4
  dependency-type: direct:development
...

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

Author: dependabot[bot]

pyproject.toml

@@ -50,7 +50,7 @@ dev = [
     "pytest-cov>=6.0.0",
     "pytest-xdist[psutil]>=3.8.0",
     "ruff>=0.11.0",
-    "sphinx>=8.2.3",
+    "sphinx>=9.0.4",
     "tox>=4.25.0",
     "tox-gh-actions>=3.5.0",
 ]