Hello,

I'm encountering an error when using online payments in POS and trying to close the session. Here's the full description:

odoo version: 18V

Steps to reproduce:

1. Configure a POS with an online payment method (e.g., Multicard) where payment_method.type == 'online'
2. Make a POS order and pay using the online payment method
3. Assign a customer to the POS order
4. Validate the order
5. Try to close the POS session

Observed behavior:

When closing the POS session, the following error is raised:

The partner of the POS online payment (id=115) could not be found