[FIX] point_of_sale: cash balance

- Go to POS application
- Click on the 3 dots of the session to open configuration
- Remove the "Cash" payment method and just keep "Bank"
- Open the session, proceed to a sell and close it.
- Try to open the session either clicking on "Close" on the kanban card

`CacheMiss` error.

opw-2116470

closes odoo/odoo#39563

Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>