Previously, it worked by default because ProhibitUsingNullableTypeParameterAgainstNotNullAnnotated
was enabled by default since 1.8, but we have to disable it because of KT-55357
Turning off the fix by default is not a breaking change per se, because
1.8 has not yet been released.
^KT-55357 Related
^KT-36770 Related
^KT-53041 Open