Disallow users from disjoining a domain

Hello,

I have a domain with over 100 user, everynow and then they come complaining that they disjoined the domain for testing purposes and such, and they need to join the domain again

note that users are local administrators on their machines and laptops

how can I disable this feature for users? or is there a way to only allow domain admins to disjoin workstations from the domain?