The most effective policy might not be to try and mechanically prevent cheating, but to explain that, this is information that you're going to need if you actually want to go into the field and if you're using copilot here you are damaging yourself in the long run.
Maybe it's not fair to give as good grades to students who are cheating on assignments as those who are actually doing the assignments, but at the end of the day is the purpose of the course to measure the student or to teach the student?