Update python_requires to Python 3.10.

Missed in #2220. Thanks @hugovk for the spot.

Author: carltongibson

setup.cfg

@@ -33,7 +33,7 @@ include_package_data = True
 install_requires =
     Django>=5.2
     asgiref>=3.9.0,<4
-python_requires = >=3.9
+python_requires = >=3.10
 
 [options.extras_require]
 tests =