[FIX] point_of_sale: remove 0€ payment line of orders

Current behavior:
When an order contains a payment line with 0€, and a customer account
payment line. Then you close the PoS and invoice the order from an other
PoS session, you get an error.

Steps to reproduce:
- Open PoS, make a new order with a payment line of 0€ and a customer
  account payment line.
- Close the session and open a new one.
- Go in the paid order, and try to invoice it.
- You get an error.

Fix:
To fix the issue we just remove the useless 0€ payment line.

opw-3477486

closes odoo/odoo#135284

X-original-commit: 24c311670164d5f06dc50d829bb653b06cf86f07
Signed-off-by: Joseph Caburnay (jcb) <jcb@odoo.com>
Signed-off-by: Robin Engels (roen) <roen@odoo.com>

addons/point_of_sale/static/src/app/screens/payment_screen/payment_screen.js

@@ -256,6 +256,11 @@ export class PaymentScreen extends Component {
         }
 
         this.currentOrder.date_order = luxon.DateTime.now();
+        for (let line of this.paymentLines) {
+            if (!line.amount === 0) {
+                 this.currentOrder.remove_paymentline(line);
+            }
+        }
         this.currentOrder.finalized = true;
 
         // 1. Save order to server.