Fix build with JDK 21

Author: technoir42

buildSrc/src/main/kotlin/com/badoo/marathon/conventions/MarathonConventionsPlugin.kt

@@ -64,7 +64,7 @@ class MarathonConventionsPlugin : Plugin<Project> {
     private fun Project.configureJava(versionCatalog: VersionCatalog) {
         extensions.configure<JavaPluginExtension> {
             toolchain {
-                languageVersion.set(JVM_TARGET)
+                languageVersion.set(JavaLanguageVersion.of(17))
             }
             withJavadocJar()
             withSourcesJar()
@@ -79,9 +79,6 @@ class MarathonConventionsPlugin : Plugin<Project> {
 
     private fun Project.configureKotlin() {
         extensions.configure<KotlinJvmProjectExtension> {
-            jvmToolchain {
-                languageVersion.set(JVM_TARGET)
-            }
             compilerOptions {
                 freeCompilerArgs.addAll(
                     "-Xjvm-default=all",
@@ -208,8 +205,4 @@ class MarathonConventionsPlugin : Plugin<Project> {
         val versionSuffix = if (releaseMode.orNull == "RELEASE") "" else "-SNAPSHOT"
         return version.get() + versionSuffix
     }
-
-    companion object {
-        private val JVM_TARGET = JavaLanguageVersion.of(17)
-    }
 }

sample/app/build.gradle.kts

@@ -4,6 +4,12 @@ plugins {
     alias(libs.plugins.marathon)
 }
 
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(17))
+    }
+}
+
 android {
     compileSdk = 34
     namespace = "com.example"
@@ -19,11 +25,6 @@ android {
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
 
-    compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_17
-        targetCompatibility = JavaVersion.VERSION_17
-    }
-
     buildTypes {
         getByName("release") {
             isMinifyEnabled = false

sample/library/build.gradle.kts

@@ -4,6 +4,12 @@ plugins {
     alias(libs.plugins.marathon)
 }
 
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(17))
+    }
+}
+
 android {
     compileSdk = 34
     namespace = "com.example.library"
@@ -14,11 +20,6 @@ android {
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
 
-    compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_17
-        targetCompatibility = JavaVersion.VERSION_17
-    }
-
     lint {
         targetSdk = 34
     }