Serialization issue with value classes and class discriminator

[ArmureSolide]

Describe the bug When trying to serialize a value class
If the ClassDiscriminatorMode is set to ALL_JSON_OBJECTS And the value class encapsulates a list Then it seems like the serializer tries to add a classDiscriminator to a list, resulting in a weird output.

This issue doesn't seem to exist if the value class encapsulates an object or a primitive

To Reproduce

@Serializable
@JvmInline
value class Test(val value: List<Int>)

@OptIn(ExperimentalSerializationApi::class)
val json: Json by lazy {
    Json {
        classDiscriminatorMode = ClassDiscriminatorMode.ALL_JSON_OBJECTS
    }
}

fun main() {
    val test = Test(value = listOf(3))
    val result = json.encodeToString(test)
    println(result) // ["type":"Test",3]
}

Expected behavior

The output should be [3]

Environment

• Kotlin version: 2.1.21
• Library version: 1.8.1