Stabilize Duration, DurationUnit and related top-level functions KT-46784

Co-authored-by: Abduqodiri Qurbonzoda <abduqodiri.qurbonzoda@jetbrains.com>

libraries/stdlib/js/src/kotlin/time/DurationUnit.kt

@@ -5,8 +5,8 @@
 
 package kotlin.time
 
-@SinceKotlin("1.3")
-@ExperimentalTime
+@SinceKotlin("1.6")
+@WasExperimental(ExperimentalTime::class)
 public actual enum class DurationUnit(internal val scale: Double) {
     /**
      * Time unit representing one nanosecond, which is 1/1000 of a microsecond.
@@ -39,7 +39,6 @@ public actual enum class DurationUnit(internal val scale: Double) {
 }
 
 @SinceKotlin("1.3")
-@ExperimentalTime
 internal actual fun convertDurationUnit(value: Double, sourceUnit: DurationUnit, targetUnit: DurationUnit): Double {
     val sourceCompareTarget = sourceUnit.scale.compareTo(targetUnit.scale)
     return when {
@@ -50,7 +49,6 @@ internal actual fun convertDurationUnit(value: Double, sourceUnit: DurationUnit,
 }
 
 @SinceKotlin("1.5")
-@ExperimentalTime
 internal actual fun convertDurationUnitOverflow(value: Long, sourceUnit: DurationUnit, targetUnit: DurationUnit): Long {
     val sourceCompareTarget = sourceUnit.scale.compareTo(targetUnit.scale)
     return when {
@@ -61,7 +59,6 @@ internal actual fun convertDurationUnitOverflow(value: Long, sourceUnit: Duratio
 }
 
 @SinceKotlin("1.5")
-@ExperimentalTime
 internal actual fun convertDurationUnit(value: Long, sourceUnit: DurationUnit, targetUnit: DurationUnit): Long {
     val sourceCompareTarget = sourceUnit.scale.compareTo(targetUnit.scale)
     return when {