Refine GrailsResourceBanner

Support Spring Boot 3

grails-boot/src/main/groovy/grails/boot/GrailsResourceBanner.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2021-2022 the original author or authors.
+ * Copyright 2021-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
  */
 package grails.boot;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -46,7 +47,7 @@ public GrailsResourceBanner(Resource resource) {
 
     @Override
     protected List<PropertyResolver> getPropertyResolvers(Environment environment, Class<?> sourceClass) {
-        List<PropertyResolver> resolvers = super.getPropertyResolvers(environment, sourceClass);
+        List<PropertyResolver> resolvers = new ArrayList<>(super.getPropertyResolvers(environment, sourceClass));
         resolvers.add(getGrailsVersionResolver(sourceClass));
         return resolvers;
     }