Update sphinx requirement from <8,>=7 to >=7,<9 (#5043)

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/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v7.0.0...v8.0.2)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

requirements-dev.txt

@@ -3,7 +3,7 @@ pytest-cov>=2.12.1,<6
 pytest-timeout>=1.4.2,<3
 stubserver>=1.1,<2
 setuptools>=65.5.1,<73
-sphinx>=7,<8
+sphinx>=7,<9
 sphinx-autoapi>=3.2.1,<4
 astroid>=3,<4
 sphinx-autodoc-typehints>=1.24.0,<3