Fixed #33572 -- Implemented CreateModel/AlterModelManagers reduction.

django/db/migrations/operations/models.py

@@ -170,6 +170,19 @@ class CreateModel(ModelOperation):
                     managers=self.managers,
                 ),
             ]
+        elif (
+            isinstance(operation, AlterModelManagers)
+            and self.name_lower == operation.name_lower
+        ):
+            return [
+                CreateModel(
+                    self.name,
+                    fields=self.fields,
+                    options=self.options,
+                    bases=self.bases,
+                    managers=operation.managers,
+                ),
+            ]
         elif (
             isinstance(operation, AlterTogetherOptionOperation)
             and self.name_lower == operation.name_lower

tests/migrations/test_optimizer.py

@@ -129,6 +129,30 @@ class OptimizerTests(SimpleTestCase):
             ],
         )
 
+    def test_create_alter_model_managers(self):
+        self.assertOptimizesTo(
+            [
+                migrations.CreateModel("Foo", fields=[]),
+                migrations.AlterModelManagers(
+                    name="Foo",
+                    managers=[
+                        ("objects", models.Manager()),
+                        ("things", models.Manager()),
+                    ],
+                ),
+            ],
+            [
+                migrations.CreateModel(
+                    "Foo",
+                    fields=[],
+                    managers=[
+                        ("objects", models.Manager()),
+                        ("things", models.Manager()),
+                    ],
+                ),
+            ],
+        )
+
     def test_create_model_and_remove_model_options(self):
         self.assertOptimizesTo(
             [