Given the success of the helicopter drone (Ingenuity) on Mars, I wonder if that's an option for cleaning solar panels - i.e. put a simple rotating brush/fan system on the drone, keep it in a port on the main lander, and every once in a while, launch it and have it land on the solar panels, where it does a roomba routine.

Since drones already expand the abilities of a lander, i.e. exploring the immediate area and collecting samples, this wouldn't be much of an added cost.