Improve mismatched sizes management when loading a pretrained model (#17257)

- Add --ignore_mismatched_sizes argument to classification examples

- Expand the error message when loading a model whose head dimensions are different from expected dimensions

examples/pytorch/image-classification/run_image_classification.py

@@ -150,6 +150,10 @@ class ModelArguments:
             )
         },
     )
+    ignore_mismatched_sizes: bool = field(
+        default=False,
+        metadata={"help": "Will enable to load a pretrained model whose head dimensions are different."},
+    )
 
 
 def collate_fn(examples):
@@ -269,6 +273,7 @@ def main():
         cache_dir=model_args.cache_dir,
         revision=model_args.model_revision,
         use_auth_token=True if model_args.use_auth_token else None,
+        ignore_mismatched_sizes=model_args.ignore_mismatched_sizes,
     )
     feature_extractor = AutoFeatureExtractor.from_pretrained(
         model_args.feature_extractor_name or model_args.model_name_or_path,