Revert "fix speed ppt eval hang (#9218)" (#9229)

This reverts commit fbe5bc1.

Author: ZHUI

paddlenlp/trainer/trainer.py

@@ -1623,7 +1623,7 @@ def get_eval_dataloader(self, eval_dataset: Optional[Dataset] = None) -> DataLoa
                 eval_dataset,
                 batch_sampler=eval_sampler,
                 collate_fn=self.data_collator,
-                num_workers=0,
+                num_workers=self.args.dataloader_num_workers,
                 **additional_configs,
             )
 
@@ -1670,7 +1670,7 @@ def get_test_dataloader(self, test_dataset: Dataset) -> DataLoader:
                 test_dataset,
                 batch_size=self.args.per_device_eval_batch_size * self.world_size,
                 collate_fn=self.data_collator,
-                num_workers=0,
+                num_workers=self.args.dataloader_num_workers,
                 **additional_config,
             )
         else: