Use Plugins DSL in Kotlin Gradle scripts

When plugins DSL is used, there is no need to
manually generate typesafe accessors for extensions and
conventions (by running `./gradlew kotlinDslAccessorsSnapshot`).

prepare/compiler-client-embeddable/build.gradle.kts

@@ -4,10 +4,9 @@ description = "Kotlin compiler client embeddable"
 
 plugins {
     maven
+    kotlin("jvm")
 }
 
-apply { plugin("kotlin") }
-
 val jarContents by configurations.creating
 val testRuntimeCompilerJar by configurations.creating
 val testStdlibJar by configurations.creating