Recover after #909 (#925)

* Fix stubs related to `(Async)RequestFactory` and `(Async)Client`

* Revert incorrect removal.

* Allow set as `unique_together`, use shared type alias.

* Revert `Q.__init__` to use only `*args, **kwargs` to remove false-positive with `Q(**{...})`

* Add abstract methods to `HttpResponseBase` to create common interface.

* Remove monkey-patched attributes from `HttpResponseBase` subclasses.

* Add QueryDict mutability checks (+ plugin support)

* Fix lint

* Return back GenericForeignKey to `Options.get_fields`

* Minor fixup

* Make plugin code typecheck with `--warn-unreachable`, minor performance increase.

* Better types for `{unique, index}_together` and Options.

* Fix odd type of `URLResolver.urlconf_name` which isn't a str actually.

* Better types for field migration operations.

* Revert form.files to `MultiValueDict[str, UploadedFile]`

* Compatibility fix (#916)

* Do not assume that `Annotated` is always related to django-stubs (fixes #893)

* Restrict `FormView.get_form` return type to `_FormT` (class type argument). Now it is resolved to `form_class` argument if present, but also errors if it is not subclass of _FormT

* Fix CI (make test runnable on 3.8)

* Fix CI (make test runnable on 3.8 _again_)

mypy_django_plugin/transformers/managers.py

@@ -263,8 +263,6 @@ def create_new_manager_class_from_from_queryset_method(ctx: DynamicClassDefConte
                     semanal_api.defer()
                 return None
             original_return_type = method_type.ret_type
-            if original_return_type is None:
-                continue
 
             # Skip any method that doesn't return _QS
             original_return_type = get_proper_type(original_return_type)