Coding challenge Git-like platform

Hey!

So lately, I've been conducting interviews for a tech job by requesting the interviewees to submit a pull request to complete a small JavaScript coding challenge to one of our private repository (this also means that I need to add them as contributors and remove them once it's done).

So GitHub is good and stuff, but for our case, it's not very handy, especially when I need to delete the entire branch by force pushing a ref to the main branch to the interviewee's branch (to prevent cheating). It feels too much hacky for me.

But I also like the fact that on pull requests, GitHub Actions gets triggered so that I am not in charge of validating the challenge (even if I always take a look at what has been done).

I've also heard about GitHub Classrooms. I've never really got deep into the documentation, but I was wondering if maybe this was the solution to my problem.

Does anyone know some good tips? How do you do that kind of stuff if you are into tech recruitment? Should I change the way I do this?

Thanks!