fix: Fix signature for GenericRelation (typeddjango#90)

Without this, invalid signature from ForeignObject was used.

Author: last-partizan

django-stubs/contrib/contenttypes/fields.pyi

@@ -84,6 +84,11 @@ class GenericRelation(ForeignObject[Any]):
     content_type_field_name: Any = ...
     for_concrete_model: Any = ...
     to_fields: Any = ...
+    def __new__(
+        cls,
+        *args: Any,
+        **kwargs: Any
+    ) -> GenericRelation: ...
     def __init__(
         self,
         to: Union[Type[Model], str],

tests/trout/models.py

@@ -8,6 +8,7 @@
 
 import psycopg2
 from django.contrib.auth.models import User as AuthUser
+from django.contrib.contenttypes.fields import GenericRelation
 from django.contrib.postgres.fields import (
     ArrayField,
     CICharField,
@@ -234,6 +235,12 @@ class Comment(models.Model):
         null=True
     )
 
+    generic_relation = GenericRelation(
+        "Post",
+        content_type_field="generic_ct",
+        object_id_field="generic_id",
+    )
+
 
 def process_non_nullable(
     x: Union[