Fix ContentType model fields to be infered as Any, refs typeddjango#2446 (typeddjango#2483)

Author: sobolevn

django-stubs/contrib/contenttypes/models.pyi

@@ -13,8 +13,8 @@ class ContentTypeManager(models.Manager[ContentType]):
 
 class ContentType(models.Model):
     id: int
-    app_label: models.CharField
-    model: models.CharField
+    app_label = models.CharField(max_length=100)
+    model = models.CharField(max_length=100)
     objects: ClassVar[ContentTypeManager]
     @property
     def name(self) -> str: ...

tests/typecheck/contrib/contenttypes/test_models.yml

@@ -0,0 +1,13 @@
+- case: test_contenttypes_models
+  main: |
+    from django.contrib.contenttypes.models import ContentType
+
+    c = ContentType.objects.create(app_label='abc', model='abc')
+    reveal_type(c.id)  # N: Revealed type is "builtins.int"
+    reveal_type(c.app_label)  # N: Revealed type is "builtins.str"
+    reveal_type(c.model)  # N: Revealed type is "builtins.str"
+
+    ContentType.objects.create(app_label=[])  # E: Incompatible type for "app_label" of "ContentType" (got "List[Any]", expected "Union[str, int, Combinable]")  [misc]
+
+  custom_settings: |
+    INSTALLED_APPS = ("django.contrib.contenttypes",)