Do not change fragment chunk-size when `--test`

Closes #3434

yt_dlp/downloader/fragment.py

@@ -177,7 +177,7 @@ class FragmentFD(FileDownloader):
                 'ratelimit': self.params.get('ratelimit'),
                 'retries': self.params.get('retries', 0),
                 'nopart': self.params.get('nopart', False),
-                'test': self.params.get('test', False),
+                'test': False,
             }
         )
         tmpfilename = self.temp_name(ctx['filename'])