fix: add max length to config

ref: https://huggingface.co/openai/whisper-large-v3/commit/7d7979efc4b8eb508fb98895b8b22770468eab18

config.json

@@ -34,6 +34,7 @@
   "mask_time_length": 10,
   "mask_time_min_masks": 2,
   "mask_time_prob": 0.05,
+  "max_length": 448,
   "max_source_positions": 1500,
   "max_target_positions": 448,
   "median_filter_width": 7,