perf(sound): optimize audio device switching performance

Filter invalid sink paths immediately before processing to avoid
unnecessary delays. Remove the 200ms blocking sleep that was originally
used for debouncing, as invalid signals are now filtered early and
valid signals arrive with sufficient intervals (typically >250ms).

This change improves UI responsiveness by eliminating the blocking
delay while maintaining stable device switching behavior.

优化音频设备切换性能

在处理前立即过滤无效的 sink 路径以避免不必要的延迟。移除原本用于
防抖的 200ms 阻塞延迟，因为无效信号现在会被提前过滤，而有效信号
到达的间隔已足够大（通常 >250ms）。

此改动通过消除阻塞延迟来提升 UI 响应速度，同时保持稳定的设备切换
行为。

Log: optimize audio device switching performance
PMS: BUG-295929

Author: mhduiy

plugins/dde-dock/sound/soundcontroller.cpp

@@ -73,17 +73,15 @@ void SoundController::SetMute(bool in0)
 
 void SoundController::onDefaultSinkChanged(const QDBusObjectPath &path)
 {
-    // 防止手动切换设备，与后端交互时，获取到多个信号，设备切换多次，造成混乱
-    QThread::msleep(200);
-
-    if (m_defaultSinkInter)
-        m_defaultSinkInter->deleteLater();
-
+    // Filter invalid sink paths immediately to avoid unnecessary processing
     if (path.path() == "/" || path.path().isEmpty()) {
         qWarning() << "default sink path is invalid, skip setting default sink interface.";
         return;
     }
 
+    if (m_defaultSinkInter)
+        m_defaultSinkInter->deleteLater();
+
     m_defaultSinkInter = new DBusSink("org.deepin.dde.Audio1", path.path(), QDBusConnection::sessionBus(), this);
 
     SoundModel::ref().setActivePort(m_defaultSinkInter->card(), m_defaultSinkInter->activePort().name);