highlightedtext throws an error basing on model (#5030)
* highlightedtext throws an error basing on model
* add changeset
* add test
---------
Co-authored-by: Abubakar Abid <abubakar@huggingface.co>
Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>