@awmatheson thank you for building this action.

It is almost exactly what I needed for an educational project I support (add checklists to students' PRs based on label assigned).

I needed support of pull_request_target event and needed it pretty fast.

In fact, I forked your repo and added this enhancement to use in that another project. I'd love to contribute to your project so this change would be available to other users of your action.

Do you mind if I open a PR on your repo?

The change to the code is really small (see the diff).