gh-108840: Remove unused TestEnumTypeSubclassing from test_enum (#108841)

Author: sobolevn

Lib/test/test_enum.py

@@ -4688,8 +4688,6 @@ def _generate_next_value_(name, start, count, last):
         self.assertEqual(Huh.TWO.value, (2, 2))
         self.assertEqual(Huh.THREE.value, (3, 3, 3))
 
-class TestEnumTypeSubclassing(unittest.TestCase):
-    pass
 
 expected_help_output_with_docs = """\
 Help on class Color in module %s: