fix remove_unused_columns (#4749)

Author: Jintao-Huang

swift/llm/argument/base_args/template_args.py

@@ -64,11 +64,12 @@ def __post_init__(self):
             self.truncation_strategy = 'delete'
 
     def get_template_kwargs(self):
+        from ..train_args import TrainArguments
         truncation_strategy = self.truncation_strategy
         if truncation_strategy == 'delete':
             truncation_strategy = 'raise'
-        remove_unused_columns = self.remove_unused_columns
-        if hasattr(self, 'rlhf_type') and self.rlhf_type == 'grpo':
+        remove_unused_columns = self.remove_unused_columns  # from DataArguments
+        if not isinstance(self, TrainArguments) or hasattr(self, 'rlhf_type') and self.rlhf_type == 'grpo':
             remove_unused_columns = True
         return {
             'default_system': self.system,