tl;tr: use kotest 4.x which doesn't have a plugin.
There is unfortunately a problem with using the latest (5.x) kotest version. It requires hotline 1.6, Atrium still uses 1.3 in order to be able to support 1.2 still (support will soon be dropped but not yet in the current version). Checkout the open WIP PR. There is still a problem that the tests don't run as they should. Maybe you see why?