In one of my college classes, after you submitted your project you'd have a short meeting with a TA and/or the professor to talk through your solution. For a smaller advanced class I think this kind of thing is feasible and can help prevent blind copy/pasting. If you wrote your code with an LLM but you're still able to have a knowledgeable conversation about it, then great, that's what you're going to do in the real world too. If you can't answer any questions about it and it seems like you don't understand your own code, then you don't get a good grade even if it works.

As an added bonus, being able to discuss your code with another engineer that wasn't involved in writing it is an important skill that might not otherwise be trained in college.