[FIX] sale_stock: forgotten field after 0cc30bf08
[FIX] sale_stock: forgotten field after 0cc30bf08

`confirmation_date` => `date_order`

closes odoo/odoo#35708

Signed-off-by: Damien Bouvy (dbo) <26cc0816b78fc1f1d6597524ae2f7230dc232c77@odoo.com>
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo