[MIRROR] Reduce Lists Memory usage, update CI (#10929)

code/game/machinery/camera/camera.dm

@@ -38,15 +38,13 @@
 
 	var/affected_by_emp_until = 0
 
-	var/client_huds = list()
-
-	var/list/camera_computers_using_this = list()
+	var/client_huds = null
 
 /obj/machinery/camera/Initialize(mapload)
 	wires = new(src)
 	assembly = new(src)
 	assembly.state = 4
-	client_huds |= GLOB.global_hud.whitense
+	LAZYOR(client_huds, GLOB.global_hud.whitense)
 
 	/* // Use this to look for cameras that have the same c_tag.
 	for(var/obj/machinery/camera/C in cameranet.cameras)

code/game/machinery/camera/motion.dm

@@ -1,5 +1,5 @@
 /obj/machinery/camera
-	var/list/motionTargets = list()
+	var/list/motionTargets = null
 	var/detectTime = 0
 	var/area/ai_monitored/area_motion = null
 	var/alarm_delay = 100 // Don't forget, there's another 10 seconds in queueAlarm()
@@ -29,13 +29,13 @@
 	if (detectTime == 0)
 		detectTime = world.time // start the clock
 	if (!(target in motionTargets))
-		motionTargets += target
+		LAZYADD(motionTargets, target)
 	return 1
 
 /obj/machinery/camera/proc/lostTarget(var/mob/target)
 	if (target in motionTargets)
-		motionTargets -= target
-	if (motionTargets.len == 0)
+		LAZYREMOVE(motionTargets, target)
+	if (LAZYLEN(motionTargets) == 0)
 		cancelAlarm()
 
 /obj/machinery/camera/proc/cancelAlarm()