accept Socket.IO disconnect reason

Update the WebSocket disconnect handler signature to accept the disconnect reason now passed by python-socketio. Agent Zero does not currently use the reason value, but keeping the parameter matches the documented Socket.IO callback shape and avoids relying on the library's legacy one-argument handler fallback. python-socketio>=5.14.2 now documents server disconnect handlers as receiving sid, reason: https://python-socketio.readthedocs.io/en/stable/server.html#connect-and-disconnect-events. The 5.14.2 source also passes that reason into the disconnect event. It still has a legacy fallback that retries old one-arg handlers, so removing it would probably work today, but only by leaning on compatibility behavior.