[ie/youtube] Deprioritize `web_safari` m3u8 formats (#14168)

Authored by: bashonly

yt_dlp/extractor/youtube/_video.py

@@ -3611,6 +3611,10 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             if f.get('source_preference') is None:
                 f['source_preference'] = -1
 
+            # Deprioritize since its pre-merged m3u8 formats may have lower quality audio streams
+            if client_name == 'web_safari' and proto == 'hls' and live_status != 'is_live':
+                f['source_preference'] -= 1
+
             if missing_pot:
                 f['format_note'] = join_nonempty(f.get('format_note'), 'MISSING POT', delim=' ')
                 f['source_preference'] -= 20