Issue #21741: Update 147 test modules to use test discovery.

I have compared output between pre- and post-patch runs of these tests
to make sure there's nothing missing and nothing broken, on both
Windows and Linux.  The only differences I found were actually tests
that were previously *not* run.

Lib/test/test_super.py

@@ -2,7 +2,6 @@
 
 import sys
 import unittest
-from test import support
 
 
 class A:
@@ -173,9 +172,5 @@ class TestSuper(unittest.TestCase):
         self.assertRaises(TypeError, X.meth, c)
 
 
-def test_main():
-    support.run_unittest(TestSuper)
-
-
 if __name__ == "__main__":
     unittest.main()