Added Model._do_update() method signature (#1854)

Add typing for a private method (used in django-fsm), which signature has not changed since 2013.

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

django-stubs/db/models/base.pyi

@@ -4,7 +4,7 @@ from typing import Any, ClassVar, Final, TypeVar, overload
 from django.core.checks.messages import CheckMessage
 from django.core.exceptions import MultipleObjectsReturned as BaseMultipleObjectsReturned
 from django.core.exceptions import ObjectDoesNotExist, ValidationError
-from django.db.models import BaseConstraint, Field
+from django.db.models import BaseConstraint, Field, QuerySet
 from django.db.models.manager import BaseManager, Manager
 from django.db.models.options import Options
 from typing_extensions import Self
@@ -49,6 +49,15 @@ class Model(metaclass=ModelBase):
     def add_to_class(cls, name: str, value: Any) -> Any: ...
     @classmethod
     def from_db(cls, db: str | None, field_names: Collection[str], values: Collection[Any]) -> Self: ...
+    def _do_update(
+        self,
+        base_qs: QuerySet[Self],
+        using: str | None,
+        pk_val: Any,
+        values: Collection[tuple[Field, type[Model] | None, Any]],
+        update_fields: Iterable[str] | None,
+        forced_update: bool,
+    ) -> bool: ...
     def delete(self, using: Any = ..., keep_parents: bool = ...) -> tuple[int, dict[str, int]]: ...
     async def adelete(self, using: Any = ..., keep_parents: bool = ...) -> tuple[int, dict[str, int]]: ...
     def full_clean(