move generated stubs to separate directory, too messty

django-stubs-generated/db/backends/sqlite3/creation.pyi

@@ -0,0 +1,11 @@
+from typing import Any, Optional, Tuple
+
+from django.db.backends.base.creation import BaseDatabaseCreation
+
+
+class DatabaseCreation(BaseDatabaseCreation):
+    connection: django.db.backends.sqlite3.base.DatabaseWrapper
+    @staticmethod
+    def is_in_memory_db(database_name: str) -> bool: ...
+    def get_test_db_clone_settings(self, suffix: Any): ...
+    def test_db_signature(self) -> Tuple[str, str]: ...