Minor Gradle build script cleanup

Author: stephan-gh

build.gradle.kts

@@ -36,7 +36,6 @@ val CI = System.getenv("CI") != null
 
 val ideaVersion: String by extra
 val javaVersion: String by extra
-val kotlinVersion: String by extra
 val downloadIdeaSources: String by extra
 
 // for publishing nightlies
@@ -236,9 +235,6 @@ java.sourceSets[SourceSet.MAIN_SOURCE_SET_NAME].java.srcDir(generate)
 // Remove gen directory on clean
 clean.delete(generate)
 
-// Workaround for KT-16764
-compileKotlin.inputs.dir(generate)
-
 runIde {
     maxHeapSize = "2G"
 
@@ -251,7 +247,7 @@ runIde {
 }
 
 inline operator fun <T : Task> T.invoke(a: T.() -> Unit): T = apply(a)
-fun DependencyHandlerScope.kotlin(module: String) = kotlin(module, kotlinVersion) as String
+fun DependencyHandlerScope.kotlin(module: String) = kotlin(module, null) as String
 fun intellijPlugin(name: String) = mapOf(
     "group" to "org.jetbrains.plugins",
     "name" to name,

gradle.properties

@@ -10,7 +10,6 @@
 # suppress inspection "UnusedProperty" for whole file
 ideaVersion = 2017.3.2
 javaVersion = 1.8
-kotlinVersion = 1.2.10
 
 group = com.demonwav.minecraft-dev
 version = 2017.3-1.1.0