Make NodeJsSetupTask and YarnSetupTask cacheable

For users that have Gradle's build cache [1] enabled, make NodeJsSetupTask
and YarnSetupTask cacheable to avoid the distribution archives being
downloaded again if they have been downloaded before by other builds of
other projects that apply the Kotlin plugin.

[1] https://docs.gradle.org/current/userguide/build_cache.html

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/nodejs/NodeJsSetupTask.kt

@@ -2,6 +2,7 @@ package org.jetbrains.kotlin.gradle.targets.js.nodejs
 
 import org.gradle.api.DefaultTask
 import org.gradle.api.artifacts.repositories.IvyPatternRepositoryLayout
+import org.gradle.api.tasks.CacheableTask
 import org.gradle.api.tasks.Input
 import org.gradle.api.tasks.OutputDirectory
 import org.gradle.api.tasks.TaskAction
@@ -11,6 +12,7 @@ import org.jetbrains.kotlin.gradle.utils.patternLayoutCompatible
 import java.io.File
 import java.net.URI
 
+@CacheableTask
 open class NodeJsSetupTask : DefaultTask() {
     private val settings get() = NodeJsRootPlugin.apply(project.rootProject)
     private val env by lazy { settings.environment }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/yarn/YarnSetupTask.kt

@@ -7,12 +7,14 @@ package org.jetbrains.kotlin.gradle.targets.js.yarn
 
 import de.undercouch.gradle.tasks.download.DownloadAction
 import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.CacheableTask
 import org.gradle.api.tasks.Input
 import org.gradle.api.tasks.OutputDirectory
 import org.gradle.api.tasks.TaskAction
 import org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootPlugin
 import java.io.File
 
+@CacheableTask
 open class YarnSetupTask : DefaultTask() {
     private val settings = project.yarn
     private val env by lazy { settings.environment }