One workaround that I know would work would be an enterprise profile. I know this because I’m one of the people tasked with blocking AI stuff at my org. How you’d implement this without a subscription to management (MDM) software I leave to you to research. I know it’s possible without proprietary tools because I’ve read about people using profiles to block software updates on their personal computers, but I don’t recall how that’s done.
You can just use Apple Configurator to make a .mobileconfig file and apply that, no MDM required.