remove audio_normalization

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>

lib/models/common/audio_normalization.dart

@@ -1,11 +0,0 @@
-enum AudioNormalization {
-  disable('禁用'),
-  // ref https://github.com/KRTirtho/spotube/commit/da10ab2e291d4ba4d3082b9a6ae535639fb8f1b7
-  dynaudnorm('预设 dynaudnorm', 'dynaudnorm=g=5:f=250:r=0.9:p=0.5'),
-  loudnorm('预设 loudnorm', 'loudnorm=I=-16:LRA=11:TP=-1.5'),
-  custom('自定义参数');
-
-  final String title;
-  final String param;
-  const AudioNormalization(this.title, [this.param = '']);
-}