fix: The 'warn' method is deprecated (#11105)

* The 'warn' method is deprecated

* fix test

examples/legacy/seq2seq/seq2seq_trainer.py

@@ -73,7 +73,7 @@ class Seq2SeqTrainer(Trainer):
             ), "Make sure that `config.pad_token_id` is correcly defined when ignoring `pad_token` for loss calculation or doing label smoothing."
 
         if self.config.pad_token_id is None and self.config.eos_token_id is not None:
-            logger.warn(
+            logger.warning(
                 f"The `config.pad_token_id` is `None`. Using `config.eos_token_id` = {self.config.eos_token_id} for padding.."
             )
 
@@ -127,7 +127,7 @@ class Seq2SeqTrainer(Trainer):
         if self.lr_scheduler is None:
             self.lr_scheduler = self._get_lr_scheduler(num_training_steps)
         else:  # ignoring --lr_scheduler
-            logger.warn("scheduler is passed to `Seq2SeqTrainer`, `--lr_scheduler` arg is ignored.")
+            logger.warning("scheduler is passed to `Seq2SeqTrainer`, `--lr_scheduler` arg is ignored.")
 
     def _get_lr_scheduler(self, num_training_steps):
         schedule_func = arg_to_scheduler[self.args.lr_scheduler]