[Gradle] Remove deprecated ways to specify compiler classpath

This change removes options to specify compiler classpath using
deprecated properties that were deprecated for more than 2 years.

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

@@ -103,25 +103,6 @@ class KotlinDaemonIT : BaseGradleIT() {
         }
     }
 
-    @Test
-    fun testGradleBuildClasspathShouldNotBeLeakedIntoDaemonClasspathOnUsingCustomCompilerJar() {
-        val testProject = Project(
-            projectName = "customCompilerFile",
-        )
-        testProject.setupWorkingDir()
-
-        // copy compiler embeddable into project dir using custom name
-        val classpath = System.getProperty("java.class.path").split(File.pathSeparator)
-        val kotlinEmbeddableJar = File(classpath.find { it.contains("kotlin-compiler-embeddable") }!!)
-
-        val compilerJar = File(testProject.projectDir, "compiler.jar")
-        kotlinEmbeddableJar.copyTo(compilerJar)
-
-        testProject.build("build") {
-            assertGradleClasspathNotLeaked()
-        }
-    }
-
     private fun CompiledProject.assertGradleClasspathNotLeaked() {
         assertContains("Kotlin compiler classpath:")
         val daemonClasspath = output.lineSequence().find {

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

@@ -367,23 +367,6 @@ class KotlinGradleIT : BaseGradleIT() {
         }
     }
 
-    @Test
-    fun testCustomCompilerFile() {
-        val project = Project("customCompilerFile")
-        project.setupWorkingDir()
-
-        // copy compiler embeddable to project dir using custom name
-        val classpath = System.getProperty("java.class.path").split(File.pathSeparator)
-        val kotlinEmbeddableJar = File(classpath.find { it.contains("kotlin-compiler-embeddable") })
-        val compilerJar = File(project.projectDir, "compiler.jar")
-        kotlinEmbeddableJar.copyTo(compilerJar)
-
-        project.build("build") {
-            assertSuccessful()
-            assertContains("Kotlin compiler classpath: $compilerJar")
-        }
-    }
-
     @Test
     fun testFreeCompilerArgs() {
         val project = Project("kotlinProject")

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

@@ -85,9 +85,9 @@ class UpToDateIT : BaseGradleIT() {
             buildGradle.appendText("""${'\n'}
                 // Add Kapt to the project to test its input checks as well:
                 apply plugin: 'kotlin-kapt'
-                compileKotlin.compilerClasspath = files($originalPaths).toList()
+                compileKotlin.getDefaultCompilerClasspath${'$'}kotlin_gradle_plugin().setFrom(files($originalPaths).toList())
                 afterEvaluate {
-                    kaptGenerateStubsKotlin.compilerClasspath = files($originalPaths).toList()
+                    kaptGenerateStubsKotlin.getDefaultCompilerClasspath${'$'}kotlin_gradle_plugin().setFrom(files($originalPaths).toList())
                 }
             """.trimIndent())
         }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/customCompilerFile/build.gradle

@@ -1,23 +0,0 @@
-buildscript {
-    repositories {
-        mavenLocal()
-        mavenCentral()
-    }
-    dependencies {
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-    }
-}
-
-apply plugin: "kotlin"
-
-repositories {
-    mavenLocal()
-    mavenCentral()
-}
-
-dependencies {
-    testImplementation 'junit:junit:4.12'
-    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
-}
-
-compileKotlin.compilerJarFile = project.file("compiler.jar")

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/customCompilerFile/src/main/kotlin/Dummy.kt

@@ -1 +0,0 @@
-class Dummy