[FIX] delivery: avoid invisible product_uom_id

Since commit 5ccc32fcf7, it's no longer
possible to write on invisible fields.

Make sure the field product_uom_id is visible to avoid a traceback.

closes odoo/odoo#97313

Signed-off-by: Josse Colpaert <jco@odoo.com>

addons/delivery/tests/test_delivery_cost.py

@@ -49,6 +49,7 @@ class TestDeliveryCost(common.TransactionCase):
             "UPDATE res_company SET currency_id = %s WHERE id = %s",
             [self.env.ref('base.USD').id, self.env.company.id])
         self.pricelist.currency_id = self.env.ref('base.USD').id
+        self.env.user.groups_id |= self.env.ref('uom.group_uom')
 
     def test_00_delivery_cost(self):
         # In order to test Carrier Cost