Mechening Part 2: Marauder And Seraph (#3049)

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## About The Pull Request
This PR resprites the final two missing mechs needed to be resprited
(No, the HONK and Reticence do not count), and makes the Mauler also
match the style. The Dark Gygax has also been touched up to match the
new palette. The sprites were made by INFRARED_BARON.


![image](https://github.com/shiptest-ss13/Shiptest/assets/77556824/95a548c2-311c-4f5b-99a7-098689c87719)

### This PR was authored with the consent of the original artist.
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## Why It's Good For The Game
Now all mechs are up to date! Let's just ignore the crafting parts...
For now. Tee hee.
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## Changelog

:cl: INFRARED_BARON
imageadd: All mechs have been successfully resprited, including the
Mauler, Marauder and Seraph now!
/:cl:

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