Update supported versions of Python

Author: Steap

setup.cfg

@@ -7,15 +7,16 @@ long_description_content_type = text/markdown
 author = The MacPorts Project
 author_email = [email protected]
 url= https://github.com/macports/upt-macports
-python_requires = >= 3.7
+python_requires = >= 3.9
 classifiers =
     Development Status :: 3 - Alpha
     License :: OSI Approved :: BSD License
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.7
-    Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
+    Programming Language :: Python :: 3.11
+    Programming Language :: Python :: 3.12
+    Programming Language :: Python :: 3.13
     Programming Language :: Python :: 3 :: Only
 
 [options]