add todo to followup in ES-11961

Author: slobodanadamovic

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/xcontent/XContentUtils.java

@@ -128,6 +128,9 @@ private static void addSubjectInfo(XContentBuilder builder, Subject subject) thr
                 }
                 builder.endObject();
             }
+            case CLOUD_API_KEY -> {
+                // TODO Add cloud API key information here
+            }
         }
     }