Update dependency Sphinx to v9

Author: renovate[bot]

setup.py

@@ -73,7 +73,7 @@ def run(self):
     tests_require=[
         'codecov>=2.0.3,<3.0.0',
         'coverage>=4.0.3,<5.0.0',
-        'Sphinx>=1.4.1,<2.0.0',
+        'Sphinx>=9.0.4,<9.1.0',
         'tox>=2.3.1,<3.0.0',
         'virtualenv>=15.0.1,<16.0.0'
     ],