Refactor deprecated Gradle settings

Author: Brutus5000

lobby/build.gradle.kts

@@ -2,7 +2,7 @@ import org.gradle.api.tasks.testing.logging.TestExceptionFormat.FULL
 import org.gradle.api.tasks.testing.logging.TestLogEvent.FAILED
 import org.gradle.api.tasks.testing.logging.TestLogEvent.STANDARD_ERROR
 import org.gradle.api.tasks.testing.logging.TestLogEvent.STANDARD_OUT
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 
 plugins {
   alias(libs.plugins.kotlin.jvm)
@@ -44,9 +44,9 @@ tasks.withType<Test> {
   systemProperties["junit.jupiter.execution.parallel.enabled"] = true
 }
 
-tasks.withType<KotlinCompile> {
-  kotlinOptions {
-    freeCompilerArgs = listOf("-Xjsr305=strict")
-    jvmTarget = "21"
+kotlin {
+  compilerOptions {
+    freeCompilerArgs.set(listOf("-Xjsr305=strict"))
+    jvmTarget.set(JvmTarget.JVM_21)
   }
 }