Removing unused imports in build.gradle (#3860)

Author: mjovanc

build.gradle

@@ -6,8 +6,6 @@
 import org.jetbrains.kotlin.config.KotlinCompilerVersion
 import org.jetbrains.kotlin.gradle.plugin.KotlinPlatformType
 import org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootExtension
-import org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootPlugin
-import org.jetbrains.kotlin.gradle.targets.js.yarn.YarnPlugin
 import org.jetbrains.kotlin.gradle.targets.js.yarn.YarnRootExtension
 import org.jetbrains.kotlin.konan.target.HostManager
 import org.jetbrains.dokka.gradle.DokkaTaskPartial