[IMP] account: remove _inherits in account_tour_upload_bill

account_tour_upload_bill is using an inherits only to use a single m2m
field. This will remove the inherits and simply add the field directly
into the account_tour_upload_bill model.

task id #2339702

closes odoo/odoo#59169

Related: odoo/upgrade#1899
Signed-off-by: William André (wan) <wan@odoo.com>

addons/account/wizard/account_tour_upload_bill.py

@@ -8,9 +8,11 @@ import base64
 class AccountTourUploadBill(models.TransientModel):
     _name = 'account.tour.upload.bill'
     _description = 'Account tour upload bill'
-    _inherits = {'mail.compose.message': 'composer_id'}
 
-    composer_id = fields.Many2one('mail.compose.message', string='Composer', required=True, ondelete='cascade')
+    attachment_ids = fields.Many2many(
+        comodel_name='ir.attachment',
+        relation='account_tour_upload_bill_ir_attachments_rel',
+        string='Attachments')
 
     selection = fields.Selection(
         selection=lambda self: self._selection_values(),