If you are not planning on sending in more inventory, you should delete the listing, so Amazon does not expect you to send in more inventory. Otherwise, this will affect your restock inventory rating which can ultimately negatively impact your IPI.
To delete an item form you inventory, select the item you wish to remove, then click on “Action on selected.” Finally, choose “delete products and listings,” from the drop down and within a couple minutes the item will be removed from your inventory.
How do I get rid of out of stock inventory?
Why are my inactive out of stock items still in my seller central inventory?