Migrate metric to Evaluate in Pytorch examples (#18369)

* Migrate metric to Evaluate in pytorch examples

* Remove unused imports

examples/pytorch/language-modeling/run_clm.py

@@ -30,8 +30,9 @@ from itertools import chain
 from typing import Optional
 
 import datasets
-from datasets import load_dataset, load_metric
+from datasets import load_dataset
 
+import evaluate
 import transformers
 from transformers import (
     CONFIG_MAPPING,
@@ -492,7 +493,7 @@ def main():
                 logits = logits[0]
             return logits.argmax(dim=-1)
 
-        metric = load_metric("accuracy")
+        metric = evaluate.load("accuracy")
 
         def compute_metrics(eval_preds):
             preds, labels = eval_preds

examples/pytorch/language-modeling/run_mlm.py

@@ -30,8 +30,9 @@ from itertools import chain
 from typing import Optional
 
 import datasets
-from datasets import load_dataset, load_metric
+from datasets import load_dataset
 
+import evaluate
 import transformers
 from transformers import (
     CONFIG_MAPPING,
@@ -515,7 +516,7 @@ def main():
                 logits = logits[0]
             return logits.argmax(dim=-1)
 
-        metric = load_metric("accuracy")
+        metric = evaluate.load("accuracy")
 
         def compute_metrics(eval_preds):
             preds, labels = eval_preds