added 2 new TargetReasons for 1.16 mob behavior

paper-api/src/main/java/org/bukkit/event/entity/EntityTargetEvent.java

@@ -159,6 +159,14 @@ public class EntityTargetEvent extends EntityEvent implements Cancellable {
          * as wheat in its hand.
          */
         TEMPT,
+        /**
+         * When the target is in a different dimension
+         */
+        TARGET_OTHER_LEVEL, // Paper
+        /**
+         * When the target is in creative or spectator gamemode, or the difficulty is peaceful, or other reasons
+         */
+        TARGET_INVALID, // Paper
         /**
          * A currently unknown reason for the entity changing target.
          */