buildSrc/build.gradle.kts

plugins {
    kotlin("jvm") version "1.8.0"
}

kotlin {
    jvmToolchain {
        languageVersion.set(JavaLanguageVersion.of(11))
    }
}

repositories {
    mavenCentral()
    maven("https://maven.pkg.jetbrains.space/kotlin/p/kotlin/bootstrap/")
}