Clean up warnings in tests in Gradle build

spring-web/src/test/java/org/springframework/web/bind/support/DefaultDataBinderFactoryTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -92,6 +92,7 @@ public class DefaultDataBinderFactoryTests {
 		public void validate(Object target, Errors errors) {
 		}
 
+		@SuppressWarnings("unchecked")
 		@Override
 		public <T> T unwrap(Class<T> type) {
 			return (T) this.validator;