Set up copyright year ratcheting (#5)

When files get updated, update the copyright year range as well.

Also, update copyright year for NOTICE.txt

Author: bioball

NOTICE.txt

@@ -1,4 +1,4 @@
-Copyright © 2024 Apple Inc. and the Pkl project authors
+Copyright © 2024-2025 Apple Inc. and the Pkl project authors
 
 Portions of this software includes code from "Gradle" by Gradle, Inc.
 

build.gradle.kts

@@ -15,11 +15,15 @@ plugins {
   alias(libs.plugins.spotless)
 }
 
+val originalRemoteName = System.getenv("PKL_ORIGINAL_REMOTE_NAME") ?: "origin"
+
 spotless {
+  ratchetFrom = "$originalRemoteName/main"
+
   kotlin {
     licenseHeader("""
             /**
-             * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+             * Copyright © ${'$'}YEAR Apple Inc. and the Pkl project authors. All rights reserved.
              *
              * Licensed under the Apache License, Version 2.0 (the "License");
              * you may not use this file except in compliance with the License.
@@ -38,7 +42,7 @@ spotless {
   format("pkl") {
     licenseHeader("""
             //===----------------------------------------------------------------------===//
-            // Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+            // Copyright © ${'$'}YEAR Apple Inc. and the Pkl project authors. All rights reserved.
             //
             // Licensed under the Apache License, Version 2.0 (the "License");
             // you may not use this file except in compliance with the License.

packages/pkl.impl.circleci/PklProject.deps.json

@@ -9,4 +9,4 @@
       }
     }
   }
-}
+}