UI: Remove legacy Qt workarounds (Ubuntu 22.04)

UI/window-basic-main.cpp

@@ -3787,14 +3787,7 @@ void OBSBasic::HideAudioControl()
 
 	if (!SourceMixerHidden(source)) {
 		SetSourceMixerHidden(source, true);
-
-		/* Due to a bug with QT 6.2.4, the version that's in the Ubuntu
-		* 22.04 ppa, hiding the audio mixer causes a crash, so defer to
-		* the next event loop to hide it. Doesn't seem to be a problem
-		* with newer versions of QT. */
-		QMetaObject::invokeMethod(this, "DeactivateAudioSource",
-					  Qt::QueuedConnection,
-					  Q_ARG(OBSSource, OBSSource(source)));
+		DeactivateAudioSource(source);
 	}
 }