Duplicate shulker entry (#3623)

src/main/resources/experience.yml

@@ -303,7 +303,6 @@ Experience:
             Rabbit: 1.0
             Chicken: 1.0
             Bat: 1.0
-            Shulker: 2.0
             Mushroom_Cow: 1.0
             Cow: 1.0
             Sheep: 1.0