[1.16] Fix MobGoals#getAllGoals not actually returning all goals (#3670)

Spigot-API-Patches/Add-Mob-Goal-API.patch

@@ -162,7 +162,11 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    MOVE,
 +    LOOK,
 +    JUMP,
-+    TARGET
++    TARGET,
++    /**
++     * Used to map vanilla goals, that are a behavior goal but don't have a type set...
++     */
++    UNKNOWN_BEHAVIOR,
 +
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/entity/ai/MobGoals.java b/src/main/java/com/destroystokyo/paper/entity/ai/MobGoals.java