[Gradle, JS] Use node_modules dir existence as marker of up-to-date

^KT-34014 fixed
^KT-49505 fixed

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-test-webpack-config/build.gradle.kts

@@ -20,7 +20,6 @@ kotlin {
             inputFileProperty.set(provider { compilation.npmProject.require("webpack/bin/webpack.js") }.map { RegularFile { File(it) } })
             dependsOn("browserDevelopmentWebpack")
             val configFile = tasks.named<org.jetbrains.kotlin.gradle.targets.js.webpack.KotlinWebpack>("browserDevelopmentWebpack").map { it.configFile }.get()
-            configFile.parentFile.listFiles().forEach { println(it)}
             args("configtest")
             args(configFile.absolutePath)
         }