Support PeftModel signature inspect (#27865)

* Support PeftModel signature inspect

* Use get_base_model() to get the base model

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Co-authored-by: shujunhua1 <shujunhua1@jd.com>

src/transformers/trainer.py

@@ -695,7 +695,10 @@ class Trainer:
     def _set_signature_columns_if_needed(self):
         if self._signature_columns is None:
             # Inspect model forward signature to keep only the arguments it accepts.
-            signature = inspect.signature(self.model.forward)
+            model_to_inspect = self.model
+            if is_peft_available() and isinstance(self.model, PeftModel):
+                model_to_inspect = self.model.get_base_model()
+            signature = inspect.signature(model_to_inspect.forward)
             self._signature_columns = list(signature.parameters.keys())
             # Labels may be named label or label_ids, the default data collator handles that.
             self._signature_columns += list(set(["label", "label_ids"] + self.label_names))