When printing a done MO with a non-tracked finished product that doesn't have a product barcode, an invalid zpl file is created (i.e. there is no end to the label in this case). Instead of an invalid label, we now write "No barcode available" to have a valid ZPL and to match what happens in the PDF version of this label. Part of task: 2494740 Part-of: odoo/odoo#82389