[Windows] ConnectionResetError WinError 10054 in asyncio after recent update

After the latest ComfyUI update, the following error appears at the end of every
audio generation (ACE-Step workflow). It did not occur before the update.

[ERROR] Exception in callback _ProactorBasePipeTransport._call_connection_lost(None)
...
ConnectionResetError: [WinError 10054]

[ERROR] Exception in callback _ProactorBasePipeTransport._call_connection_lost(None)
handle:
Traceback (most recent call last):
File "C:\IA LOCAL\PROGRAMAS\IA_IMAGEN\Data\Assets\Python\cpython-3.12.12-windows-x86_64-none\Lib\asyncio\events.py", line 88, in _run
self._context.run(self._callback, *self._args)
File "C:\IA LOCAL\PROGRAMAS\IA_IMAGEN\Data\Assets\Python\cpython-3.12.12-windows-x86_64-none\Lib\asyncio\proactor_events.py", line 165, in _call_connection_lost
self._sock.shutdown(socket.SHUT_RDWR)
ConnectionResetError: [WinError 10054] Se ha forzado la interrupción de una conexión existente por el host remoto

Workflow type: ACE-Step audio generation (T2A)
Error occurs immediately after KSampler completes (50/50 steps).
The frontend closes the websocket upon receiving the completion signal,
while Python's ProactorEventLoop still attempts socket.shutdown(SHUT_RDWR),
causing WinError 10054. VAE decode has started at this point.

OS: Windows
Python: 3.12.12
Installed via: Stability Matrix
GPU: RTX 4060 Ti 8GB

Audio generates correctly — this appears to be a cosmetic regression in websocket
shutdown handling on Windows (ProactorEventLoop). Did not occur on previous version.

Reproduce the ACE-Step T2A workflow on Windows and observe the completion signal, websocket close, and subsequent _ProactorBasePipeTransport._call_connection_lost traceback in Python's asyncio/proactor_events.py. Compare the frontend websocket shutdown with the ProactorEventLoop socket shutdown; done means audio still generates without the WinError 10054 traceback.

Written by the indexing model from the issue text.