use new spawncommand for pumpkins, adjust parameters a bit

init.lua

@@ -70,6 +70,16 @@ mobs:register_mob("halloween_mobs:pumpkin", {
         }
 })
 
-mobs:register_spawn("halloween_mobs:pumpkin", {"air","air"}, 20, 10, 900, 2, 31000, true)
+mobs:spawn({
+    name = "halloween_mobs:pumpkin", 
+    nodes = "air",
+    neighbors = "air",
+    interval = 1,
+    chance = 1,
+    active_object_count = 1,
+    day_toggle = nil,
+    min_height = 0,
+    max_height = 60
+})
 
 mobs:register_egg("halloween_mobs:pumpkin", "Flying Pumpkin", "default_cloud.png", 1)