Refs #23919 -- Removed reset_warning_registry() workaround for Python…

… < 3.4.2.

django/test/utils.py

@@ -768,20 +768,6 @@ def captured_stdin():
     return captured_output("stdin")
 
 
-def reset_warning_registry():
-    """
-    Clear warning registry for all modules. This is required in some tests
-    because of a bug in Python that prevents warnings.simplefilter("always")
-    from always making warnings appear: http://bugs.python.org/issue4180
-
-    The bug was fixed in Python 3.4.2.
-    """
-    key = "__warningregistry__"
-    for mod in sys.modules.values():
-        if hasattr(mod, key):
-            getattr(mod, key).clear()
-
-
 @contextmanager
 def freeze_time(t):
     """

tests/deprecation/tests.py

@@ -1,7 +1,6 @@
 import warnings
 
 from django.test import SimpleTestCase
-from django.test.utils import reset_warning_registry
 from django.utils.deprecation import (
     DeprecationInstanceCheck, RemovedInNextVersionWarning, RenameMethodsBase,
 )
@@ -24,7 +23,6 @@ def test_class_definition_warnings(self):
         Ensure a warning is raised upon class definition to suggest renaming
         the faulty method.
         """
-        reset_warning_registry()
         with warnings.catch_warnings(record=True) as recorded:
             warnings.simplefilter('always')