Migrate repo to use JVM toolchains Gradle feature.

^KT-46972 Fixed

libraries/tools/kotlin-annotations-jvm/build.gradle

@@ -2,7 +2,9 @@ description = 'Kotlin annotations for JVM'
 
 apply plugin: 'kotlin'
 
-configureJvm6Project(project)
+JvmToolchain.configureJvmToolchain(project, JdkMajorVersion.JDK_1_6)
+LibrariesCommon.disableDeprecatedJvmTargetWarning(project)
+
 configurePublishing(project)
 
 sourceSets {
@@ -20,11 +22,6 @@ dependencies {
 configureSourcesJar()
 configureJavadocJar()
 
-tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile) {
-    kotlinOptions.jdkHome = JDK_16
-    kotlinOptions.jvmTarget = 1.6
-}
-
 compileKotlin {
     kotlinOptions.freeCompilerArgs = [
             "-Xallow-kotlin-package",