add back await content_send_channel.aclose()

Author: bjoaquinc

src/mcp/server/streaming_asgi_transport.py

@@ -174,6 +174,7 @@ async def process_messages() -> None:
                 # Ensure events are set even if there's an error
                 initial_response_ready.set()
                 response_complete.set()
+                await content_send_channel.aclose()
 
 
         # Create tasks for running the app and processing messages