set queue max_size to 12

app.py

@@ -127,5 +127,5 @@ with gr.Blocks(css=css) as app:
         show_api = False
     )
 
-app.queue(api_open=False).launch(share=False, show_api=False)
+app.queue(max_size=12, api_open=False).launch(share=False, show_api=False)