Update trainer.py

sentence_transformers/trainer.py

@@ -498,7 +498,7 @@ def _load_best_model(self) -> None:
         if not isinstance(self.model[0], Transformer):
             logger.info("Could not load best model, as the model is not a `transformers`-based model.")
             return
-        elif isinstance(self.model[0], PeftAdapterMixin):
+        elif isinstance(self.model[0].auto_model, PeftAdapterMixin):
             logger.info("Could not load best model, as the model is a `PeftAdapterMixin`-based model. Please wait for an update of the transformers library to enable this feature.")
             return