[ie/youtube] Suppress "Unavailable videos are hidden" warning (#10159)

Authored by: mgedmin

yt_dlp/extractor/youtube.py

@@ -468,7 +468,10 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
         'si', 'th', 'lo', 'my', 'ka', 'am', 'km', 'zh-CN', 'zh-TW', 'zh-HK', 'ja', 'ko',
     ]
 
-    _IGNORED_WARNINGS = {'Unavailable videos will be hidden during playback'}
+    _IGNORED_WARNINGS = {
+        'Unavailable videos will be hidden during playback',
+        'Unavailable videos are hidden',
+    }
 
     _YT_HANDLE_RE = r'@[\w.-]{3,30}'  # https://support.google.com/youtube/answer/11585688?hl=en
     _YT_CHANNEL_UCID_RE = r'UC[\w-]{22}'