Improve Field.formfield(), GeometryField.formfield() methods (#1724)

Co-authored-by: Marti Raudsepp <marti@juffo.org>

Author: brianhelba

django-stubs/contrib/gis/db/models/fields.pyi

@@ -108,7 +108,9 @@ class GeometryField(BaseSpatialField[_ST, _GT]):
         validators: Iterable[_ValidatorCallable] = ...,
         error_messages: _ErrorMessagesMapping | None = ...,
     ) -> None: ...
-    def formfield(self, **kwargs: Any) -> Any: ...  # type: ignore[override]
+    def formfield(  # type: ignore[override]
+        self, *, form_class: type[GeometryField] | None = ..., geom_type: str = ..., srid: Any = ..., **kwargs: Any
+    ) -> GeometryField: ...
     def select_format(self, compiler: Any, sql: Any, params: Any) -> Any: ...
 
 class PointField(GeometryField[_ST, _GT]):

django-stubs/db/models/fields/__init__.pyi

@@ -205,8 +205,8 @@ class Field(RegisterLookupMixin, Generic[_ST, _GT]):
     # TODO: plugin support
     def formfield(
         self,
-        form_class: type[forms.Field] | None = ...,
-        choices_form_class: Any | None = ...,
+        form_class: type[Field] | None = ...,
+        choices_form_class: type[forms.ChoiceField] | None = ...,
         **kwargs: Any,
     ) -> Field: ...
     def save_form_data(self, instance: Model, data: Any) -> None: ...