Speeds up init by ignoring contrib guidelines (#16217)

code/controllers/subsystems/air.dm

@@ -138,7 +138,10 @@ Class Procs:
 	admin_notice(SPAN_DANGER("Processing Geometry..."), R_DEBUG)
 
 	var/simulated_turf_count = 0
-	for(var/turf/simulated/S in turfs)
+	for(var/turf/T in world)
+		var/turf/simulated/S = T
+		if(!istype(S))
+			continue
 		simulated_turf_count++
 		S.update_air_properties()
 

code/controllers/subsystems/initialization/xenoarch.dm

@@ -21,10 +21,11 @@ var/datum/controller/subsystem/xenoarch/SSxenoarch
 	set background=1
 
 	//create digsites
-	for(var/turf/simulated/mineral/M in turfs)
+	for(var/turf/TIW in world)
 		CHECK_TICK
+		var/turf/simulated/mineral/M = TIW
 
-		if(!prob(XENOARCH_SPAWN_CHANCE))
+		if(!istype(M) || !prob(XENOARCH_SPAWN_CHANCE))
 			continue
 
 		digsite_spawning_turfs.Add(M)