[FIX] stock_picking_batch: cancel confirmed batches without transfers

Steps to reproduce the bug:
- Create a batch transfer with several pickings
- Confirm it
- Delete all the pickings > save

Problem:
The batch does not cancel as it should’ve been
A batch without transfers cannot be confirmed, so it makes no sense to leave a confirmed batch without transfers

opw-2792471

closes odoo/odoo#89815

Signed-off-by: Steve Van Essche <svs@odoo.com>