[3.10] bpo-45229: Remove test_main in many tests (GH-28405) (GH-28455)

Instead of explicitly enumerate test classes for run_unittest()
use the unittest ability to discover tests. This also makes these
tests discoverable and runnable with unittest.

load_tests() can be used for dynamic generating tests and adding
doctests. setUpModule(), tearDownModule() and addModuleCleanup()
can be used for running code before and after all module tests.
(cherry picked from commit 40348acc180580371d25f75f46b27048e35f2435)
diff --git a/Lib/test/test_profile.py b/Lib/test/test_profile.py
index 7de7d52..d97fe44 100644
--- a/Lib/test/test_profile.py
+++ b/Lib/test/test_profile.py
@@ -6,7 +6,6 @@
 import os
 from difflib import unified_diff
 from io import StringIO
-from test.support import run_unittest
 from test.support.os_helper import TESTFN, unlink, temp_dir, change_cwd
 from contextlib import contextmanager
 
@@ -156,12 +155,10 @@ def silent():
     finally:
         sys.stdout = stdout
 
-def test_main():
-    run_unittest(ProfileTest)
 
 def main():
     if '-r' not in sys.argv:
-        test_main()
+        unittest.main()
     else:
         regenerate_expected_output(__file__, ProfileTest)