fix: 模式切换时音频残余，优化相关状态管理

main/xiaozhi-server/core/handle/receiveAudioHandle.py

@@ -17,7 +17,6 @@ async def handleAudioMessage(conn, audio):
     if hasattr(conn, "just_woken_up") and conn.just_woken_up:
         have_voice = False
         # 设置一个短暂延迟后恢复VAD检测
-        conn.asr_audio.clear()
         if not hasattr(conn, "vad_resume_task") or conn.vad_resume_task.done():
             conn.vad_resume_task = asyncio.create_task(resume_vad_detection(conn))
         return