Do not consider 'expect' class type constructors final

Because even a final expected class can be actualized with an open
actual class and thus have subtypes in the platform code

core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedClassDescriptor.kt

@@ -195,8 +195,6 @@ class DeserializedClassDescriptor(
 
         override fun getParameters() = parameters()
 
-        override fun isFinal(): Boolean = isFinalClass
-
         override fun isDenotable() = true
 
         override fun getDeclarationDescriptor() = this@DeserializedClassDescriptor