Remove message_factory_test_wrapper for python's message_factory_test.

The test wrappers were another way to document nonconformant behaviour between
different python backends. We can achieve the same by removing the wrapper
script and adding an if-condition in the test itself based on
api_implementation.Type(). Since we already do that for nonconformance between
pure Python vs. C++ backends, this change makes it easier to look for UPB
nonconformance instead of going through another layer of indirection.

PiperOrigin-RevId: 700127942

python/google/protobuf/internal/message_factory_test.py

@@ -179,19 +179,34 @@ def testDuplicateExtensionNumber(self):
         type_name='Duplicate',
         extendee='Container',
     )
-    pool.Add(f)
+    if api_implementation.Type() == 'upb':
+      with self.assertRaisesRegex(
+          TypeError,
+          # TODO - b/380939902: Figure out why this fails with an OOM message.
+          "Couldn't build proto file into descriptor pool: out of memory",
+      ):
+        pool.Add(f)
+    else:
+      pool.Add(f)
 
-    with self.assertRaises(Exception) as cm:
-      message_factory.GetMessageClassesForFiles([f.name], pool)
+      with self.assertRaises(Exception) as cm:
+        message_factory.GetMessageClassesForFiles([f.name], pool)
 
-    self.assertIn(str(cm.exception),
-                  ['Extensions '
-                   '"google.protobuf.python.internal.Duplicate.extension_field" and'
-                   ' "google.protobuf.python.internal.Extension.extension_field"'
-                   ' both try to extend message type'
-                   ' "google.protobuf.python.internal.Container"'
-                   ' with field number 2.',
-                   'Double registration of Extensions'])
+      self.assertIn(
+          str(cm.exception),
+          [
+              (
+                  'Extensions'
+                  ' "google.protobuf.python.internal.Duplicate.extension_field"'
+                  ' and'
+                  ' "google.protobuf.python.internal.Extension.extension_field"'
+                  ' both try to extend message type'
+                  ' "google.protobuf.python.internal.Container" with field'
+                  ' number 2.'
+              ),
+              'Double registration of Extensions',
+          ],
+      )
 
   def testExtensionValueInDifferentFile(self):
     # Add Container message.

python/pb_unit_tests/BUILD

@@ -17,8 +17,6 @@ pyproto_test_wrapper(name = "descriptor_test")
 
 pyproto_test_wrapper(name = "generator_test")
 
-pyproto_test_wrapper(name = "message_factory_test")
-
 pyproto_test_wrapper(name = "proto_builder_test")
 
 pyproto_test_wrapper(name = "reflection_test")