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`).

libraries/tools/kotlin-annotation-processing/build.gradle.kts

@@ -4,7 +4,9 @@ import org.gradle.jvm.tasks.Jar
 
 description = "Annotation Processor wrapper for Kotlin"
 
-apply { plugin("kotlin") }
+plugins {
+    kotlin("jvm")
+}
 
 val packedJars by configurations.creating