fixup! cleaned up, DAMPified, and added tests to ensure fixtures only add ther finalizer to a dependee fixture once

Author: blueyed

testing/python/fixtures.py

@@ -4426,7 +4426,6 @@ def test_suffix(fix_combined):
 
 
 class TestFinalizerOnlyAddedOnce:
-
     @pytest.fixture(scope="class", autouse=True)
     def a(self):
         pass