Minor: dereference archiveFile when logging it

Previously it was "Plugin artifacts packed to task ':zipPlugin' property 'archiveFile'"
After fix it's    "Plugin artifacts packed to /home/bobko/jb/kotlin/build/kotlin-plugin.zip"

`archiveFile` has type `Provider<RegularFile>`

build.gradle.kts

@@ -961,7 +961,7 @@ val zipPlugin by task<Zip> {
     setExecutablePermissions()
 
     doLast {
-        logger.lifecycle("Plugin artifacts packed to $archiveFile")
+        logger.lifecycle("Plugin artifacts packed to ${archiveFile.get()}")
     }
 }