Fir2Ir: more precise calculation of enum class modality

Use the same condition as in the already existing `createIrEnumEntry`
function (and as in psi2ir): enum class should be final unless there's
an enum entry with any declaration other than its constructor.

 #KT-57216

compiler/testData/codegen/bytecodeListing/enumEntries.kt

@@ -3,9 +3,6 @@
 // FULL_JDK
 // WITH_STDLIB
 
-// IGNORE_BACKEND_K2: JVM_IR
-// FIR status: KT-57216 K2: non-trivial enum declaration does not have ACC_FINAL in the bytecode
-
 enum class SimpleEnum {
     A, B, C
 }