Fix incorrect default value for callback (#13678)

Author: tvanbaak

stubs/Flask-SocketIO/flask_socketio/test_client.pyi

@@ -29,7 +29,7 @@ class SocketIOTestClient:
         auth: dict[str, Incomplete] | None = None,
     ) -> None: ...
     def disconnect(self, namespace: str | None = None) -> None: ...
-    def emit(self, event: str, *args, callback: bool = True, namespace: str | None = None) -> Incomplete | None: ...
+    def emit(self, event: str, *args, callback: bool = False, namespace: str | None = None) -> Incomplete | None: ...
     def send(
         self,
         data: str | dict[str, Incomplete] | list[Incomplete],