fix: remove references to nonexistent keys in vqgan dataset test (#1206)

The __main__ test block accessed batch["features"] and
batch["feature_lengths"], but VQGANCollator only returns "audios"
and "audio_lengths", causing a KeyError when running the file directly.

Made-with: Cursor

fish_speech/datasets/vqgan.py

@@ -141,7 +141,5 @@ if __name__ == "__main__":
 
     for batch in dataloader:
         print(batch["audios"].shape)
-        print(batch["features"].shape)
         print(batch["audio_lengths"])
-        print(batch["feature_lengths"])
         break