Use spotless to format remaining Kotlin files

Also: fix issue where some commented out Kotlin files are invalid.

buildSrc/src/main/kotlin/pklJavaLibrary.gradle.kts

@@ -1,3 +1,18 @@
+/**
+ * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 @file:Suppress("HttpUrlsUsage")
 
 import org.gradle.accessors.dm.LibrariesForLibs
@@ -30,11 +45,14 @@ spotless {
     targetExclude("**/generated/**", "**/build/**")
     licenseHeaderFile(rootProject.file("buildSrc/src/main/resources/license-header.star-block.txt"))
   }
+  kotlin {
+    ktfmt(libs.versions.ktfmt.get()).googleStyle()
+    targetExclude("**/generated/**", "**/build/**")
+    licenseHeaderFile(rootProject.file("buildSrc/src/main/resources/license-header.star-block.txt"))
+  }
 }
 
-tasks.compileKotlin {
-  enabled = false
-}
+tasks.compileKotlin { enabled = false }
 
 tasks.jar {
   manifest {
@@ -49,15 +67,18 @@ tasks.javadoc {
   (options as StandardJavadocDocletOptions).addStringOption("Xdoclint:none", "-quiet")
 }
 
-val workAroundKotlinGradlePluginBug by tasks.registering {
-  doLast {
-    // Works around this problem, which sporadically appears and disappears in different subprojects:
-    // A problem was found with the configuration of task ':pkl-executor:compileJava' (type 'JavaCompile').
-    // > Directory '[...]/pkl/pkl-executor/build/classes/kotlin/main'
-    // specified for property 'compileKotlinOutputClasses' does not exist.
-    layout.buildDirectory.dir("classes/kotlin/main").get().asFile.mkdirs()
+val workAroundKotlinGradlePluginBug by
+  tasks.registering {
+    doLast {
+      // Works around this problem, which sporadically appears and disappears in different
+      // subprojects:
+      // A problem was found with the configuration of task ':pkl-executor:compileJava' (type
+      // 'JavaCompile').
+      // > Directory '[...]/pkl/pkl-executor/build/classes/kotlin/main'
+      // specified for property 'compileKotlinOutputClasses' does not exist.
+      layout.buildDirectory.dir("classes/kotlin/main").get().asFile.mkdirs()
+    }
   }
-}
 
 tasks.compileJava {
   dependsOn(workAroundKotlinGradlePluginBug)