Remove default method

Author: jzheaux

core/src/main/java/org/springframework/security/authorization/AuthorizationProxyFactory.java

@@ -37,15 +37,4 @@ public interface AuthorizationProxyFactory {
 	 */
 	Object proxy(Object object);
 
-	default Object requireProxy(Object object) {
-		if (object == null) {
-			return null;
-		}
-		Object proxy = proxy(object);
-		if (proxy == object) {
-			throw new IllegalArgumentException("Failed to proxy object");
-		}
-		return proxy;
-	}
-
 }