kotlin/kotlin-formal with Go target 4.13.0 does not work

[kaby76]

https://github.com/antlr/grammars-v4/actions/runs/6265803494/job/17015394126

Test failed.
infix fun box(): String {
assertEquals(KVariance.INVARIANT, ((if (true) {
(::listOfStrings)
} else {
(::listOfStrings)
}))!!.returnType.arguments.first().variance)
}