Continue to assign homework. Tie the homework to in class assessment such that if a student can do well on homework, without AI assistance, they are expected to do well on tests conducted in class, again without AI assistance.
Set homework grades to be a relatively small percentage of the final grade.
With the above framework, a student is incentivized to complete homework. If they cheat themselves and use AI, they'll do badly on the tests and badly in the class overall.
Tell the students about the above rationale. Tell them that they're not to use AI for homework, that you can't stop them from using AI, but that by using AI, all they get is a perfect score on homework and probably a bad overall grade.