LibWeb: Prefix AK::Duration with AK Namespace

Author: https://github.com/ADKaster
Commit: b20a1d0fcd
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/676
Reviewed-by: https://github.com/AtkinsSJ ✅
Reviewed-by: https://github.com/trflynn89 ✅

Userland/Libraries/LibWeb/HTML/AudioTrack.cpp

@@ -70,7 +70,7 @@ void AudioTrack::pause(Badge<HTMLAudioElement>)
     m_audio_plugin->pause_playback();
 }
 
-Duration AudioTrack::duration()
+AK::Duration AudioTrack::duration()
 {
     return m_audio_plugin->duration();
 }