[FIX] base: Automated action default update path

Before this commit, the default update_path even if the field was
readonly, it weas returned. So, if you try to create an automated
action on the stock.move.line model and try to add an action, the
button return a traceback because the field is readonly.

After this commit, the method that get the default update_path will
also check if the field is not readonly.

Bugfix Task-Id: 3624328

closes odoo/odoo#146166

Signed-off-by: Bouvy Damien (dbo) <dbo@odoo.com>

odoo/addons/base/models/ir_actions.py

@@ -468,7 +468,7 @@ class IrActionsServer(models.Model):
         model = self.env[ir_model.model]
         sensible_default_fields = ['partner_id', 'user_id', 'user_ids', 'stage_id', 'state', 'active']
         for field_name in sensible_default_fields:
-            if field_name in model._fields:
+            if field_name in model._fields and not model._fields[field_name].readonly:
                 return field_name
         return ''