Migrate repo to use JVM toolchains Gradle feature.

^KT-46972 Fixed

libraries/scripting/common/build.gradle.kts

@@ -3,7 +3,7 @@ plugins {
     id("jps-compatible")
 }
 
-jvmTarget = "1.6"
+project.updateJvmTarget("1.6")
 
 dependencies {
     compile(kotlinStdlib())

libraries/scripting/dependencies-maven/build.gradle.kts

@@ -3,7 +3,7 @@ plugins {
     id("jps-compatible")
 }
 
-jvmTarget = "1.6"
+project.updateJvmTarget("1.6")
 
 configurations.implementation {
     /**

libraries/scripting/dependencies/build.gradle.kts

@@ -3,7 +3,7 @@ plugins {
     id("jps-compatible")
 }
 
-jvmTarget = "1.6"
+project.updateJvmTarget("1.6")
 
 dependencies {
     compile(kotlinStdlib())

libraries/scripting/intellij/build.gradle.kts

@@ -4,8 +4,6 @@ plugins {
     id("jps-compatible")
 }
 
-jvmTarget = "1.8"
-
 dependencies {
     compile(project(":kotlin-script-runtime"))
     compile(kotlinStdlib())

libraries/scripting/jvm/build.gradle.kts

@@ -3,9 +3,7 @@ plugins {
     id("jps-compatible")
 }
 
-val JDK_16: String by project
-jvmTarget = "1.6"
-javaHome = JDK_16
+project.configureJvmToolchain(JdkMajorVersion.JDK_1_6)
 
 dependencies {
     compile(project(":kotlin-script-runtime"))
@@ -26,10 +24,6 @@ tasks.withType<org.jetbrains.kotlin.gradle.dsl.KotlinCompile<*>> {
     )
 }
 
-tasks.withType<Test> {
-    executable = "$JDK_16/bin/java"
-}
-
 publish()
 
 runtimeJar()