[K/N][build] Composite build with build.tools-conventions plugin

Adds convention plugin instead of sources inclusion
inside the buildSrc, effectively reducing the amount
of the code to be compiled in buildSrc.

Merge-request: KT-MR-8898

kotlin-native/Interop/Indexer/build.gradle.kts

@@ -24,7 +24,8 @@ import org.jetbrains.kotlin.konan.target.HostManager.Companion.hostIsMac
 
 plugins {
     `kotlin`
-    `native-interop-plugin`
+    id("kotlin.native.build-tools-conventions")
+    id("native-interop-plugin")
     `native`
 }
 

kotlin-native/Interop/Runtime/build.gradle.kts

@@ -16,8 +16,6 @@
 import org.jetbrains.gradle.plugins.tools.lib
 import org.jetbrains.gradle.plugins.tools.solib
 import org.jetbrains.kotlin.*
-import org.jetbrains.kotlin.konan.target.HostManager
-import java.io.ByteArrayOutputStream
 
 val kotlinVersion = project.bootstrapKotlinVersion
 plugins {