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.
diff --git a/Lib/test/test_kqueue.py b/Lib/test/test_kqueue.py
index 2585ca6..f822024 100644
--- a/Lib/test/test_kqueue.py
+++ b/Lib/test/test_kqueue.py
@@ -9,7 +9,6 @@
 import time
 import unittest
 
-from test import support
 if not hasattr(select, "kqueue"):
     raise unittest.SkipTest("test works only on BSD")
 
@@ -237,8 +236,5 @@
         self.assertEqual(os.get_inheritable(kqueue.fileno()), False)
 
 
-def test_main():
-    support.run_unittest(TestKQueue)
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()