[FIX] point_of_sale: fix onchange pricelist

Since ORM changes, the ids a many2many are new (virtual) ones in a
onchange, so we have to point to origin which are the real records to
check that the many2one is in as it has a real id.

closes odoo/odoo#33763

Signed-off-by: pimodoo <pimodoo@users.noreply.github.com>

addons/point_of_sale/models/pos_config.py

@@ -283,7 +283,7 @@ class PosConfig(models.Model):
 
     @api.onchange('available_pricelist_ids')
     def _onchange_available_pricelist_ids(self):
-        if self.pricelist_id not in self.available_pricelist_ids:
+        if self.pricelist_id not in self.available_pricelist_ids._origin:
             self.pricelist_id = False
 
     @api.onchange('is_posbox')