Remove unused WriteCopyrightToFile gradle task

#KTI-758

buildSrc/src/main/kotlin/copyright.kt

@@ -1,54 +0,0 @@
-/*
- * Copyright 2000-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package tasks
-
-import groovy.util.Node
-import groovy.xml.XmlParser
-import org.gradle.api.DefaultTask
-import org.gradle.api.file.RegularFileProperty
-import org.gradle.api.provider.Property
-import org.gradle.api.tasks.Input
-import org.gradle.api.tasks.InputFile
-import org.gradle.api.tasks.OutputFile
-import org.gradle.api.tasks.TaskAction
-import java.util.*
-
-abstract class WriteCopyrightToFile : DefaultTask() {
-    @InputFile
-    val path = project.file("${project.rootDir}/.idea/copyright/apache.xml")
-
-    @get:OutputFile
-    abstract val outputFile: RegularFileProperty
-
-    @get:Input
-    val commented: Property<Boolean> = project.objects.property(Boolean::class.java).convention(true)
-
-    @TaskAction
-    fun write() {
-        val file = outputFile.asFile.get()
-        file.writeText(if (commented.get()) readCopyrightCommented() else readCopyright())
-    }
-
-    private fun readCopyright(): String {
-        assert(path.exists()) {
-            "File $path with copyright not found"
-        }
-
-        val xmlParser = XmlParser()
-        val node = xmlParser.parse(path)
-        assert(node.attribute("name") == "CopyrightManager") {
-            "Format changed occasionally?"
-        }
-
-        val copyrightBlock = node.children().filterIsInstance<Node>().single()
-        val noticeNode = copyrightBlock.children().filterIsInstance<Node>().single { it.attribute("name") == "notice" }
-        return noticeNode.attribute("value").toString().replace("&#36;today.year", GregorianCalendar()[Calendar.YEAR].toString())
-    }
-
-    private fun readCopyrightCommented(): String {
-        return "/*\n" + readCopyright().prependIndent(" * ") + "\n */"
-    }
-}