Add freethreaded input to actions/setup-python@v5 (#59)

Author: krzema12

typings/actions/setup-python/v5/action-types.yml

@@ -29,6 +29,8 @@ inputs:
     type: boolean
   allow-prereleases:
     type: boolean
+  freethreaded:
+    type: boolean
 outputs:
   python-version:
     type: string