Upgraded to Kotlin 1.5.31 and JDK 17.

samples/kotlin/build.gradle.kts

@@ -1,6 +1,9 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
 plugins {
     id("application")
-    kotlin("jvm") version "1.5.21"
+    id("com.github.ben-manes.versions") version "0.39.0"
+    kotlin("jvm") version "1.5.30"
 }
 
 // ./gradlew run
@@ -19,3 +22,9 @@ dependencies {
 application {
     mainClass.set("net.thauvin.erik.pinboard.samples.KotlinExampleKt")
 }
+
+tasks {
+    withType<KotlinCompile>().configureEach {
+        kotlinOptions.jvmTarget = java.targetCompatibility.toString()
+    }
+}