[FIX] point_of_sale: Open cashdrawer with change

We should open the cashdrawer when paying with a non cash payment
method if change should be returned to the customer.

Use case: The customer wants to pay 10€ more with his card to get 10€
in cash in return.

closes odoo/odoo#65246

Taskid: 2449312
Signed-off-by: Quentin Lejeune (qle) <qle@odoo.com>