[FIX] mrp: always assign allowed_mo_ids

PR: odoo/odoo#113475 replaced the computation of allowed_mo_ids with a
`pass` since this field was no longer needed anymore but could not be
removed in a stable version. This breaks the unbuild flow since this
value must be assigned and throws a ValueError without it, therefore
we now default allowed_mo_ids = False to avoid this error. (i.e. cannot
open any existing unbuild records + cannot validate new unbuilds)

closes odoo/odoo#113824

Signed-off-by: Arnold Moyaux (arm) <arm@odoo.com>

addons/mrp/models/mrp_unbuild.py

@@ -78,7 +78,7 @@ class MrpUnbuild(models.Model):
 
     def _compute_allowed_mo_ids(self):
         # the function remains as a stable fix patch that was removed in master
-        pass
+        self.allowed_mo_ids = False
 
     @api.onchange('company_id')
     def _onchange_company_id(self):