Update sphinx requirement in /sdks/python

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)
- [Commits](sphinx-doc/sphinx@v1.5.2...v7.2.4)

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

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

sdks/python/setup.py

@@ -234,7 +234,7 @@ def get_portability_package_data():
       # BEAM-8840: Do NOT use tests_require or setup_requires.
       extras_require={
           'docs': [
-              'Sphinx>=1.5.2,<2.0',
+              'Sphinx>=1.5.2,<8.0',
               # Pinning docutils as a workaround for Sphinx issue:
               # https://github.com/sphinx-doc/sphinx/issues/9727
               'docutils==0.17.1'