user_idle_processor: add missing parent cleanup()

src/pipecat/processors/user_idle_processor.py

@@ -156,6 +156,7 @@ class UserIdleProcessor(FrameProcessor):
 
     async def cleanup(self) -> None:
         """Cleans up resources when processor is shutting down."""
+        await super().cleanup()
         if self._idle_task:  # Only stop if task exists
             await self._stop()