Use Plugins DSL in Kotlin Gradle scripts

When plugins DSL is used, there is no need to
manually generate typesafe accessors for extensions and
conventions (by running `./gradlew kotlinDslAccessorsSnapshot`).

js/js.tests/build.gradle.kts

@@ -3,6 +3,8 @@ import com.moowork.gradle.node.npm.NpmExecRunner
 import com.moowork.gradle.node.npm.NpmTask
 
 plugins {
+    kotlin("jvm")
+    id("jps-compatible")
     id("com.moowork.node").version("1.2.0")
 }
 
@@ -10,9 +12,6 @@ node {
     download = true
 }
 
-apply { plugin("kotlin") }
-apply { plugin("jps-compatible") }
-
 val antLauncherJar by configurations.creating
 
 dependencies {