Corrects 200+ instances of "it's" where it should've been "its" instead (#85169)

## About The Pull Request

it's - conjunction of "it" and "is"
its - possessive form of "it"

grammar is hard, and there were a lot of places where "it's" was used
where it shouldn't have been. i went and painstakingly searched the
entire repository for these instances, spending a few hours on it. i
completely ignored the changelog archive, and i may have missed some
outliers. most player-facing ones should be corrected, though
## Why It's Good For The Game
proper grammar is good

## Changelog
🆑
spellcheck: Numerous instances of "it's" have been properly replaced
with "its"
/🆑

code/game/objects/structures/deployable_turret.dm

@@ -213,7 +213,7 @@
 
 /obj/machinery/deployable_turret/hmg
 	name = "heavy machine gun turret"
-	desc = "A heavy caliber machine gun commonly used by Nanotrasen forces, famed for it's ability to give people on the receiving end more holes than normal."
+	desc = "A heavy caliber machine gun commonly used by Nanotrasen forces, famed for its ability to give people on the receiving end more holes than normal."
 	icon_state = "hmg"
 	max_integrity = 250
 	projectile_type = /obj/projectile/bullet/manned_turret/hmg