Removes network ID and some minor other things (#74789)

## About The Pull Request

Removes network_id as it was completely unused now.

Also reworks the maints access secret buttons to work with how accesses
work now, taking into account req_one_access. This is theoretically a
problem when we moved to req_one_access more often in maints so
departments can access their own maint areas.

## Why It's Good For The Game

This is just minor changes I found while trying to edit other things,
and thought I should PR it.

## Changelog

🆑
admin: Secret buttons for Engineering/Brig maint accesses should now
work more consistently.
/🆑

code/modules/admin/verbs/debug.dm

@@ -310,7 +310,7 @@
 			areas_with_multiple_APCs.Add(A.type)
 		CHECK_TICK
 
-	for(var/obj/machinery/airalarm/AA in GLOB.machines)
+	for(var/obj/machinery/airalarm/AA in GLOB.air_alarms)
 		var/area/A = get_area(AA)
 		if(!A) //Make sure the target isn't inside an object, which results in runtimes.
 			dat += "Skipped over [AA] in invalid location, [AA.loc].<br>"