Removes Xenoborgs

[FloFluoro]

What Does This PR Do

This PR removes Xenoborgs and their associated module. Xenomorph MMIs implanted into Cyborgs will now get the standard module selection.

Why It's Good For The Game

Xenoborgs were created for an ill-fated Xenomorph gamemode (#67) over 9 years ago, which itself was removed 6 years ago (#5627). Since then, they've only existed in the codebase as a half-functional novelty module for Alien MMIs.

In Issue #19290, it was noted that Xenoborgs are broken in multiple ways, namely that their toxin synthesizer spray doesn't work. The issue creator also had this to say:

the actual purpose of the Xenoborg is questionable at best.

The deeper I dug into Xenoborg code, the more I agreed with this.

	name = "paralytic toxin synthesizer"
	desc = "squirts viagra."
	list_reagents = list("ether" = 250)

If fixed, Xenoborgs would have 250u of instantly-metabolized ether at their disposal. This is not acceptable. Ether is such a problematic chem that it was the impetus behind the removal of public syringe guns (#17818), and is no longer available in medchem vendors (#18904). Security are implicitly discouraged from using ether to incapacitate criminals in all but the most severe situations; why on earth would we want a cyborg module that comes stocked with it by default?

	name = "acid synthesizer"
	desc = "squirts burny liquids."
	list_reagents = list("facid" = 125, "sacid" = 125)

If fixed, Xenoborgs would have 250u of acid to spray onto people as they please. This has no practical application outside of validhunting and casual griefing, neither of which seems appropriate for borgs on conventional lawsets.

Everything about the Xenoborg module, head to toe, was designed under the assumption that you are going to be knocking out, obstructing, or grievously injuring humans. That might've been fine for the antiquated gamemode Xenoborgs were made for, but it's not fine for a lawed silicon built by the station roboticist.

I believe that fixing Xenoborgs to reflect intended behavior would cause more problems than outright removing them, and considering they basically haven't been touched since Ponies added them almost a decade ago, I don't think anyone is chomping at the bit to salvage Xenoborgs as a concept. They weren't missed for the years Xenomorphs were off rotation, so I can't imagine they'll be missed now.

Testing

Compiled and tested on local debug server. Alien MMIs implanted into cyborgs load default modules fine.

Changelog

:cl: del: Removed Xenoborg module. Alien MMIs inserted into Cyborgs now can choose from conventional modules. /:cl: