UniqueSecurityAnnotationScanner should consider annotation on target class level as fallback

[quaff]

public abstract class AbstractController {

	@GetMapping("/get")
	public String get() {
		return "OK";
	}

}

@RestController
@Secured("USER")
public class DemoController extends AbstractController {

	/*
	public String get() {
		return super.get();
	}
	*/
}

demoController.get() is not protected by @Secured("USER"), we have to redefine it again.

I tried to fix it by adding

		annotations = findClosestClassAnnotations(targetClass, new HashSet<>());
		if (!annotations.isEmpty()) {
			return annotations;
		}

after

spring-security/core/src/main/java/org/springframework/security/core/annotation/UniqueSecurityAnnotationScanner.java

Lines 159 to 162 in b9f3a28

	annotations = findClosestClassAnnotations(specificMethod.getDeclaringClass(), new HashSet<>());
	if (!annotations.isEmpty()) {
	return annotations;
	}

but it broken GH-15352.

[quaff]

Spring Security should skip intercepting @ExceptionHandler methods other than ignore annotations on target class.