fix export format

Former-commit-id: 7c82bd396b9e6ff395850ad544d95cbf1b7557cd

src/llmtuner/hparams/model_args.py

@@ -102,6 +102,10 @@ class ModelArguments:
         default=1024,
         metadata={"help": "The maximum length of the model inputs used for quantization."}
     )
+    export_lecacy_format: Optional[bool] = field(
+        default=False,
+        metadata={"help": "Whether or not to save the `.bin` files instead of `.safetensors`."}
+    )
 
     def __post_init__(self):
         self.compute_dtype = None