[Gradle] Fix classpath cache key in ClassLoadersCachingBuildService

Lists have defined contracts for equals and hashCode and thus might be used as map keys for the sake of caching. Gradle's file collections do not follow those contracts, leading to cache misses and creating too many classloaders.
#KT-61426 Fixed

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/ClassLoadersCachingBuildService.kt

@@ -33,13 +33,14 @@ internal abstract class ClassLoadersCachingBuildService : BuildService<BuildServ
     private val logger = Logging.getLogger(javaClass)
 
     fun getClassLoader(
-        classpath: Iterable<File>,
+        classpath: List<File>,
         parentClassLoaderProvider: ParentClassLoaderProvider = DefaultParentClassLoaderProvider()
-    ) =
-        classLoaders.computeIfAbsent(ClassLoaderCacheKey(classpath, parentClassLoaderProvider)) {
+    ): ClassLoader {
+        return classLoaders.computeIfAbsent(ClassLoaderCacheKey(classpath, parentClassLoaderProvider)) {
             logger.debug("Creating a new classloader for classpath $classpath")
             URLClassLoader(classpath.map { it.toURI().toURL() }.toTypedArray(), parentClassLoaderProvider.getClassLoader())
         }
+    }
 
     override fun close() {
         logger.debug("Clearing ${classLoaders.size} cached classloaders")
@@ -59,7 +60,7 @@ internal abstract class ClassLoadersCachingBuildService : BuildService<BuildServ
 }
 
 private data class ClassLoaderCacheKey(
-    val classpath: Iterable<File>,
+    val classpath: List<File>,
     val parentClassLoaderProvider: ParentClassLoaderProvider,
 )
 

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/transforms/BuildToolsApiClasspathEntrySnapshotTransform.kt

@@ -50,7 +50,7 @@ abstract class BuildToolsApiClasspathEntrySnapshotTransform : TransformAction<Bu
 
         try {
             val classLoader = parameters.classLoadersCachingService.get()
-                .getClassLoader(parameters.classpath, SharedApiClassesClassLoaderProvider)
+                .getClassLoader(parameters.classpath.toList(), SharedApiClassesClassLoaderProvider)
             val compilationService = CompilationService.loadImplementation(classLoader)
             val snapshot = compilationService.calculateClasspathSnapshot(classpathEntryInputDirOrJar, granularity)
             snapshot.saveSnapshot(snapshotOutputFile)