Citizens NPC head not dropping

### CraftBook Version

craftbook-bukkit-5.0.0-SNAPSHOT-dist

### Platform Version

paper-1.21.4-227

### Confirmations

- [x] I am using the most recent Minecraft release.
- [x] I am using a version of WorldEdit compatible with my Minecraft version.
- [x] I am using a version of CraftBook compatible with my Minecraft version.
- [x] I am using the latest or recommended version of my platform software.
- [x] I am NOT using a hybrid server, e.g. a server that combines Bukkit and Forge. Examples include Arclight, Mohist, and Cardboard.
- [x] I am NOT using a fork of WorldEdit, such as FastAsyncWorldEdit (FAWE) or AsyncWorldEdit (AWE)

### Bug Description

I have combat NPC of the Citizens plugin on my server. Players fight with them and when they kill them, the head should drop from the NPC, but it doesn't drop and there is an error in the console https://pastebin.com/VZq2BFTQ

### Expected Behavior

The NPC head should fall out

### Reproduction Steps

1. Killing NPCs
2. The head didn't fall out
3. Error in console

### Anything Else?

_No response_