Thanatometabolizing effect can be use on predators and synthetic when they are dead.

### Testmerges

N/A

### Description of the bug

Normally chems don't works on predators and synthetics because they have a special metabolism but when they are dead, we can use on they thanatometabolizing effect because now they have "dead body metabolism" ( we can only inject chems into synthetic with cryo cell or acid vest). This mean that we can mix some effects like Defibrillating + burn/brute healing and we can revive predator as humans or we can mix Defibrillating + Repairing and make synthetic self healing.

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

They should keep special metabolism even after dead?

### How do we reproduce this bug?

1a.Make customs stims with Thanatometabolizing + Repairing + Defibrillating for Synth (Regulating for avoid OD)
1b.Make customs stims with Thanatometabolizing + Neogenetic/Anticorrosive + Defibrillating for predator (Regulating for avoid OD)
2. Inject chem into alive predators/synthetic
3. Kill him and check how chems working on him

### 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)