Gradle, JS: make KotlinWebpack.configDirectory optional

#KT-31013

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmResolver.kt

@@ -48,7 +48,10 @@ internal class NpmResolver private constructor(val rootProject: Project) {
             else {
                 val resolver = NpmResolver(rootProject)
                 check(resolver.resolve(rootProject, null))
-                ResolvedNow(ResolvedProject(resolver.npmPackages, resolver.requiredByTasks))
+                val resolution = ResolvedProject(resolver.npmPackages, resolver.requiredByTasks)
+                ProjectData[rootProject]!!.resolved = resolution
+
+                ResolvedNow(resolution)
             }
         }
 

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/webpack/KotlinWebpack.kt

@@ -47,8 +47,8 @@ open class KotlinWebpack : DefaultTask(), RequiresNpmDependencies {
     open val outputPath: File
         @OutputDirectory get() = project.buildDir.resolve("lib")
 
-    open val configDirectory: File
-        @InputDirectory get() = project.projectDir.resolve("webpack.config.d")
+    open val configDirectory: File?
+        @Optional @InputDirectory get() = project.projectDir.resolve("webpack.config.d").takeIf { it.isDirectory }
 
     @Input
     var report: Boolean = false

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/webpack/KotlinWebpackConfig.kt

@@ -18,7 +18,7 @@ class KotlinWebpackConfig(
     val entry: File,
     val reportEvaluatedConfigFile: File?,
     val outputPath: File,
-    val configDirectory: File,
+    val configDirectory: File?,
     val reportDir: File?,
     var devServer: DevServer? = null,
     val showProgress: Boolean = false,
@@ -116,8 +116,11 @@ config.plugins.push(new BundleAnalyzerPlugin(${json(config)}));
             )
         }
 
-        appendln()
-        loadConfigs(configDirectory)
+        if (configDirectory != null) {
+            appendln()
+            loadConfigs(configDirectory)
+        }
+
         appendln()
 
         if (reportEvaluatedConfigFile != null) {