[extractor/web.archive:youtube] Fix _YT_INITIAL_PLAYER_RESPONSE_RE

yt_dlp/extractor/archiveorg.py

@@ -526,9 +526,10 @@ class YoutubeWebArchiveIE(InfoExtractor):
         },
     ]
     _YT_INITIAL_DATA_RE = YoutubeBaseInfoExtractor._YT_INITIAL_DATA_RE
-    _YT_INITIAL_PLAYER_RESPONSE_RE = fr'''(?x)
+    _YT_INITIAL_PLAYER_RESPONSE_RE = fr'''(?x:
         (?:window\s*\[\s*["\']ytInitialPlayerResponse["\']\s*\]|ytInitialPlayerResponse)\s*=[(\s]*|
-        {YoutubeBaseInfoExtractor._YT_INITIAL_PLAYER_RESPONSE_RE}'''
+        {YoutubeBaseInfoExtractor._YT_INITIAL_PLAYER_RESPONSE_RE}
+    )'''
 
     _YT_DEFAULT_THUMB_SERVERS = ['i.ytimg.com']  # thumbnails most likely archived on these servers
     _YT_ALL_THUMB_SERVERS = orderedSet(