Makes addtimer(..., 0) more akin to spawn(0) (#23669)

* Makes addtimer(..., 0) use spawn(0)

* Jess queue it

* No negative times

code/controllers/subsystem/timer.dm

@@ -294,9 +294,7 @@ proc/addtimer(datum/callback/callback, wait, flags)
 	if (!callback)
 		return
 
-	if (wait <= 0)
-		callback.InvokeAsync()
-		return
+	wait = max(wait, 0)
 
 	var/hash