Synth armour sprite change (#3728)

# About the pull request

The sprite for the Synthetic utility vest/armour is now slimmer.

# Explain why it's good for the game

Fat synthetics not required for service. 


# Testing Photographs and Procedure
<summary>Screenshots & Videos</summary>

![Screenshot 2023-06-26 17 37
24](https://github.com/cmss13-devs/cmss13/assets/6595389/bbd61ad5-26ed-4e1a-a8bb-83cdcd825922)

Left is new sprite. Right is current sprite.




# Changelog
:cl:
imageadd: Synth utility vest is now slimmer in appearance
/:cl:

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Co-authored-by: Steelpoint <[email protected]>