Strays away from GLOB.machines when possible (#71100)

## About The Pull Request

This replaces needless GLOB.machines with more precise lists whenever
one existed, plus adding a new one for CTF machines.

## Why It's Good For The Game

GLOB.machines holds every single /obj/machinery in the game, so checking
the whole list for stuff is pretty big. This aims to cut that down by
using smaller lists whenever possible. I also gave CTF a new list
because it checked machines very often.

## Changelog

Nothing player facing.

code/game/machinery/embedded_controller/access_controller.dm

@@ -53,7 +53,7 @@
 		if(A.idSelf == idSelf)
 			controller = A
 			break
-	for(var/obj/machinery/door/airlock/I in GLOB.machines)
+	for(var/obj/machinery/door/airlock/I in GLOB.airlocks)
 		if(I.id_tag == idDoor)
 			door = I
 			break