[FIX] point_of_sale: open POS sessions with restricted categories

Current behaviour:
We get a traceback when opening a POS session with restricted categories

Expected behaviour:
We should be able to start a POS session with restricted categories.

Steps to reproduce:
- Install POS
- In POS global settings add any category in the restricted categories
- Try opening a new POS session

Reason for the problem:
Incorrect domain right leaf, the reference field that is a pos.category
is not de-referenced.

Fix:
Add `.ids` at the tail end of the record reference

Affected versions:
- 16.0
- master

opw-3021490

closes odoo/odoo#103548

X-original-commit: 8c76afc161133b78239cf91d746a159d67f67c4e
Signed-off-by: Grazioso Andrea (agr) <agr@odoo.com>
Signed-off-by: Piryns Victor (pivi) <pivi@odoo.com>

addons/point_of_sale/models/pos_config.py

@@ -495,7 +495,7 @@ class PosConfig(models.Model):
         # check if there's any product for this PoS
         domain = [('available_in_pos', '=', True)]
         if self.limit_categories and self.iface_available_categ_ids:
-            domain.append(('pos_categ_id', 'in', self.iface_available_categ_ids))
+            domain.append(('pos_categ_id', 'in', self.iface_available_categ_ids.ids))
         if not self.env['product.product'].search(domain):
             return {
                 'name': _("There is no products linked to your PoS"),