Hellhounds not using the proper death message and sound

### Testmerges

irrelevant

### Round ID

_No response_

### Description of the bug

Hellhounds when they die use the xeno death message and sound instead of its own custom message and its roar emote as its death sound.

### What's the difference with what should have happened?

Expected behavior: Hellhound dies > death message and sound is the hellhound one

Current behavior: Hellhound dies > death message and sound is xeno one

### How do we reproduce this bug?

1. die as Hellhound
2. watch the chat for death message and hear its death sound

### Issue Bingo

- [x] Issue could be reproduced at least once
- [x] Issue happened in a recent (less than 7 days ago) round
- [x] Couldn't find an existing issue about this (https://github.com/cmss13-devs/cmss13/issues)