chore: configure Kotlin for explicit languageVersion, coreLibrariesVersion

Author: vlsi

buildSrc/build.gradle.kts

@@ -1,5 +1,6 @@
 import org.gradle.kotlin.dsl.support.expectedKotlinDslPluginsVersion
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
 import org.jetbrains.kotlin.gradle.tasks.KotlinJvmCompile
 
 /*
@@ -62,8 +63,13 @@ fun Project.applyKotlinProjectConventions() {
     tasks.withType<JavaCompile>().configureEach {
         options.release.set(11)
     }
-    tasks.withType<KotlinJvmCompile>().configureEach {
+    kotlin {
+        @Suppress("DEPRECATION")
+        val targetKotlinVersion = KotlinVersion.KOTLIN_1_4
+
         compilerOptions {
+            apiVersion.set(targetKotlinVersion)
+            languageVersion.set(targetKotlinVersion)
             jvmTarget = JvmTarget.JVM_11
             freeCompilerArgs.add("-Xjdk-release=11")
         }

buildSrc/src/main/kotlin/build.kotlin-conventions.gradle.kts

@@ -17,20 +17,23 @@
 
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
-import org.jetbrains.kotlin.gradle.tasks.KotlinJvmCompile
 
 plugins {
     id("build.java-conventions")
     id("com.github.autostyle")
     kotlin("jvm")
 }
 
-tasks.withType<KotlinJvmCompile>().configureEach {
+kotlin {
+    @Suppress("DEPRECATION")
+    val targetKotlinVersion = KotlinVersion.KOTLIN_1_4
+
+    coreLibrariesVersion = "1.4.32"
     compilerOptions {
-        freeCompilerArgs.add("-Xjdk-release=8")
-        @Suppress("DEPRECATION")
-        apiVersion.set(KotlinVersion.KOTLIN_1_4)
         jvmTarget = JvmTarget.JVM_1_8
+        freeCompilerArgs.add("-Xjdk-release=8")
+        apiVersion.set(targetKotlinVersion)
+        languageVersion.set(targetKotlinVersion)
     }
 }