[Gradle][Minor] Move KotlinOnlyTarget into separate source file

KT-54312

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/AbstractKotlinTarget.kt

@@ -6,7 +6,6 @@ package org.jetbrains.kotlin.gradle.plugin.mpp
 
 import org.gradle.api.Action
 import org.gradle.api.DomainObjectSet
-import org.gradle.api.NamedDomainObjectContainer
 import org.gradle.api.Project
 import org.gradle.api.artifacts.ConfigurablePublishArtifact
 import org.gradle.api.artifacts.PublishArtifact
@@ -232,17 +231,3 @@ internal fun KotlinTarget.disambiguateName(simpleName: String) =
 
 internal fun javaApiUsageForMavenScoping() = "java-api-jars"
 
-abstract class KotlinOnlyTarget<T : KotlinCompilation<*>>(
-    project: Project,
-    override val platformType: KotlinPlatformType
-) : AbstractKotlinTarget(project) {
-
-    override lateinit var compilations: NamedDomainObjectContainer<T>
-        internal set
-
-    override lateinit var targetName: String
-        internal set
-
-    override var disambiguationClassifier: String? = null
-        internal set
-}

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinOnlyTarget.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2010-2022 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 org.jetbrains.kotlin.gradle.plugin.mpp
+
+import org.gradle.api.NamedDomainObjectContainer
+import org.gradle.api.Project
+import org.jetbrains.kotlin.gradle.plugin.KotlinCompilation
+import org.jetbrains.kotlin.gradle.plugin.KotlinPlatformType
+
+abstract class KotlinOnlyTarget<T : KotlinCompilation<*>>(
+    project: Project,
+    override val platformType: KotlinPlatformType
+) : AbstractKotlinTarget(project) {
+
+    override lateinit var compilations: NamedDomainObjectContainer<T>
+        internal set
+
+    override lateinit var targetName: String
+        internal set
+
+    override var disambiguationClassifier: String? = null
+        internal set
+}