Revert "revive test_flags"

This reverts commit b39ca1a.

Author: ever0de

Lib/test/test_class.py

@@ -885,10 +885,6 @@ class VarSizedSubclass(tuple):
 
 class TestInlineValues(unittest.TestCase):
 
-    def test_flags(self):
-        self.assertEqual(Plain.__flags__ & Py_TPFLAGS_MANAGED_DICT, Py_TPFLAGS_MANAGED_DICT)
-        self.assertEqual(WithAttrs.__flags__ & Py_TPFLAGS_MANAGED_DICT, Py_TPFLAGS_MANAGED_DICT)
-
     def test_no_flags_for_slots_class(self):
         flags = NoManagedDict.__flags__
         self.assertEqual(flags & Py_TPFLAGS_MANAGED_DICT, 0)