[NO GBP] Lazy Template Cordoning | Double Runtime Fix (#72709)

## About The Pull Request

Adds automatic cordoning to block reservations.
Also fixes an issue where ChangeTurf would cause SSicon_smoothing to
throw runtimes by calling QUEUE_SMOOTH regardless of initialization
completion

## Why It's Good For The Game

## Changelog

---------

Signed-off-by: GitHub <noreply@github.com>
Co-authored-by: LemonInTheDark <58055496+LemonInTheDark@users.noreply.github.com>

code/modules/shuttle/shuttle.dm

@@ -560,7 +560,9 @@
 	unregister()
 	destination = null
 	previous = null
-	QDEL_NULL(assigned_transit) //don't need it where we're goin'!
+	if(!QDELETED(assigned_transit))
+		qdel(assigned_transit, force = TRUE)
+		assigned_transit = null
 	shuttle_areas = null
 	remove_ripples()
 	return ..()