[Gradle] Register default kapt classes dir as an output

#KT-59256 Fixed

Author: ALikhachev

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/Kapt3IT.kt

@@ -1272,7 +1272,6 @@ open class Kapt3IT : Kapt3BaseIT() {
 
     @DisplayName("KT-59256: kapt generated files are included into the test runtime classpath")
     @GradleTest
-    @Disabled("The fix is not yet provided")
     fun testKaptGeneratedInTestRuntimeClasspath(gradleVersion: GradleVersion) {
         project("kapt-in-test-runtime-classpath".withPrefix, gradleVersion) {
             build("test") {

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/Kapt3KotlinGradleSubplugin.kt

@@ -382,8 +382,7 @@ class Kapt3GradleSubplugin @Inject internal constructor(private val registry: To
             // Workaround for changes in Gradle 7.3 causing eager task realization
             // For details check `KotlinSourceSetProcessor.prepareKotlinCompileTask()`
             if (kotlinCompilation is KotlinWithJavaCompilation<*, *>) {
-                val kotlinSourceDirectorySet = kotlinCompilation.defaultSourceSet.kotlin
-                kotlinSourceDirectorySet.compiledBy(taskProvider, KaptTask::classesDir)
+                kotlinCompilation.output.classesDirs.from(classesOutputDir).builtBy(taskProvider)
             } else {
                 kotlinCompilation.output.classesDirs.from(taskProvider.flatMap { it.classesDir })
             }