[extractor/youtube:tab] Detect `videoRenderer` in `_post_thread_continuation_entries`

yt_dlp/extractor/youtube.py

@@ -4063,9 +4063,12 @@ class YoutubeTabBaseInfoExtractor(YoutubeBaseInfoExtractor):
             return
         for content in contents:
             renderer = content.get('backstagePostThreadRenderer')
-            if not isinstance(renderer, dict):
+            if isinstance(renderer, dict):
+                yield from self._post_thread_entries(renderer)
                 continue
-            yield from self._post_thread_entries(renderer)
+            renderer = content.get('videoRenderer')
+            if isinstance(renderer, dict):
+                yield self._video_entry(renderer)
 
     r''' # unused
     def _rich_grid_entries(self, contents):