fixes hugginface/transformers#33420
Author: ChintanShahDS
Pull request: yes

The issue is as the label_names need to be derived from the base model and not the peft model. Changed that code to get the label_names from base model in peft cases.

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Comments:
Fix for peft related issue with the labels. Need to get the base model to get the labels argument for a peft model. Fixes #33420