Update java-toolchain sample to use Kotlin DSL

Author: bigdaz

.github/workflow-samples/java-toolchain/build.gradle renamed to .github/workflow-samples/java-toolchain/build.gradle.kts

@@ -1,5 +1,5 @@
 plugins {
-    id 'java'
+    java
 }
 
 java {
@@ -12,6 +12,10 @@ repositories {
     mavenCentral()
 }
 
-dependencies {
-    testImplementation('junit:junit:4.13.2')
-}
+testing {
+    suites {
+        val test by getting(JvmTestSuite::class) {
+            useJUnit()
+        }
+    }
+}

.github/workflow-samples/java-toolchain/settings.gradle

@@ -0,0 +1,6 @@
+plugins {
+    // Apply the foojay-resolver plugin to allow automatic download of JDKs
+    id("org.gradle.toolchains.foojay-resolver-convention") version "0.9.0"
+}
+
+rootProject.name = "java-toolchains"