Polish "Use pattern matching for instanceof where appropriate"

See gh-31475

buildSrc/src/main/java/org/springframework/boot/build/bom/BomExtension.java

@@ -315,7 +315,7 @@ public class BomExtension {
 			public Object methodMissing(String name, Object args) {
 				if (args instanceof Object[] && ((Object[]) args).length == 1) {
 					Object arg = ((Object[]) args)[0];
-					if (arg instanceof Closure closure) {
+					if (arg instanceof Closure<?> closure) {
 						ModuleHandler moduleHandler = new ModuleHandler();
 						closure.setResolveStrategy(Closure.DELEGATE_FIRST);
 						closure.setDelegate(moduleHandler);