fix: backend format test

backend/apps/images/utils/comfyui.py

 import asyncio
 import websocket  # NOTE: websocket-client (https://github.com/websocket-client/websocket-client)
-import uuid
 import json
 import urllib.request
 import urllib.parse
@@ -398,7 +397,9 @@ async def comfyui_generate_image(
         return None
 
     try:
-        images = await asyncio.to_thread(get_images, ws, comfyui_prompt, client_id, base_url)
+        images = await asyncio.to_thread(
+            get_images, ws, comfyui_prompt, client_id, base_url
+        )
     except Exception as e:
         log.exception(f"Error while receiving images: {e}")
         images = None