Use JVM toolchain for configuring source/target compilation compatibility

build.gradle.kts

@@ -1,5 +1,4 @@
 import org.jetbrains.changelog.markdownToHTML
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 fun properties(key: String) = project.findProperty(key).toString()
 
@@ -24,6 +23,13 @@ repositories {
     mavenCentral()
 }
 
+// Set the JVM language level used to compile sources and generate files - Java 11 is required since 2020.3
+kotlin {
+    jvmToolchain {
+        (this as JavaToolchainSpec).languageVersion.set(JavaLanguageVersion.of(11))
+    }
+}
+
 // Configure Gradle IntelliJ Plugin - read more: https://github.com/JetBrains/gradle-intellij-plugin
 intellij {
     pluginName.set(properties("pluginName"))
@@ -49,17 +55,6 @@ qodana {
 }
 
 tasks {
-    // Set the JVM compatibility versions
-    properties("javaVersion").let {
-        withType<JavaCompile> {
-            sourceCompatibility = it
-            targetCompatibility = it
-        }
-        withType<KotlinCompile> {
-            kotlinOptions.jvmTarget = it
-        }
-    }
-
     wrapper {
         gradleVersion = properties("gradleVersion")
     }