It's not possible as far as I know, either you restrict it to the entire network or you don't restrict it.
You can try blocking the URL via Group Policy, but I'm almost 100% sure it won't work.
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.