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.

1 files changed, 1 insertions, 12 deletions

diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index 1daa8f8a7e..bd935ede18 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -710,16 +710,5 @@ LAERTES
 """
 
 
-def test_main():
-    support.run_unittest(
-        VersionTestCase,
-        ChecksumTestCase,
-        ChecksumBigBufferTestCase,
-        ExceptionTestCase,
-        CompressTestCase,
-        CompressObjectTestCase
-    )
-
 if __name__ == "__main__":
-    unittest.main() # XXX
-    ###test_main()
+    unittest.main()