Issue #26668: Remove the redundant Lib/test/test_importlib/regrtest.py

Lib/test/test_importlib/regrtest.py

-"""Run Python's standard test suite using importlib.__import__.
-
-Tests known to fail because of assumptions that importlib (properly)
-invalidates are automatically skipped if the entire test suite is run.
-Otherwise all command-line options valid for test.regrtest are also valid for
-this script.
-
-"""
-import importlib
-import sys
-from test import libregrtest
-
-if __name__ == '__main__':
-    __builtins__.__import__ = importlib.__import__
-    sys.path_importer_cache.clear()
-
-    libregrtest.main(quiet=True, verbose2=True)