[s] Prevent unbreakable ladders from being moved by shuttles (#38477)

* Prevent unbreakable ladders from being moved by shuttles

* Disconnect ladders before and reconnect them after shuttle move

code/game/objects/structures/ladders.dm

@@ -23,13 +23,7 @@
 /obj/structure/ladder/Destroy(force)
 	if ((resistance_flags & INDESTRUCTIBLE) && !force)
 		return QDEL_HINT_LETMELIVE
-
-	if(up && up.down == src)
-		up.down = null
-		up.update_icon()
-	if(down && down.up == src)
-		down.up = null
-		down.update_icon()
+	disconnect()
 	return ..()
 
 /obj/structure/ladder/LateInitialize()
@@ -52,6 +46,15 @@
 
 	update_icon()
 
+/obj/structure/ladder/proc/disconnect()
+	if(up && up.down == src)
+		up.down = null
+		up.update_icon()
+	if(down && down.up == src)
+		down.up = null
+		down.update_icon()
+	up = down = null
+
 /obj/structure/ladder/update_icon()
 	if(up && down)
 		icon_state = "ladder11"