move generated stubs to separate directory, too messty

django-stubs-generated/db/backends/base/validation.pyi

@@ -0,0 +1,11 @@
+from typing import Any, List, Optional
+
+from django.db.backends.base.base import BaseDatabaseWrapper
+from django.db.models.fields import Field
+
+
+class BaseDatabaseValidation:
+    connection: django.db.backends.sqlite3.base.DatabaseWrapper = ...
+    def __init__(self, connection: BaseDatabaseWrapper) -> None: ...
+    def check(self, **kwargs: Any) -> List[Any]: ...
+    def check_field(self, field: Field, **kwargs: Any) -> List[Any]: ...