Remove the datum pool (#2873)

Removes the datum pool.

New-qdel is faster than pooling, and we didn't use it anyways.

code/ATMOSPHERICS/datum_pipeline.dm

@@ -22,11 +22,6 @@
 
 	return ..()
 
-/datum/pipeline/resetVariables()
-	..("members", "edges")
-	members = list()
-	edges = list()
-
 /datum/pipeline/process()//This use to be called called from the pipe networks
 	//Check to see if pressure is within acceptable limits
 	var/pressure = air.return_pressure()