fix: drop unsupported show_api kwarg on prompt.submit (Gradio 6)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app.py

@@ -596,7 +596,7 @@ with gr.Blocks(fill_height=True) as demo:
     )
     prompt.submit(
         fn=generate_and_upload, inputs=gen_inputs,
-        outputs=[output_image, used_seed, r2_status], show_api=False,
+        outputs=[output_image, used_seed, r2_status],
     )
 
 if __name__ == "__main__":