move generated stubs to separate directory, too messty

django-stubs/db/backends/postgresql/client.pyi

@@ -1,10 +0,0 @@
-from typing import Any, Dict, Optional
-
-from django.db.backends.base.client import BaseDatabaseClient
-
-
-class DatabaseClient(BaseDatabaseClient):
-    executable_name: str = ...
-    @classmethod
-    def runshell_db(cls, conn_params: Dict[str, str]) -> None: ...
-    def runshell(self) -> None: ...