[FIX] stock: allow cancelling picking with no move lines

before this commit, trying to cancel a picking with no move lines, will not move the picking to the cancel state.

* create a new picking
* keep move lines empty
* click on the cancel button
* picking will remain in the draft state

after this commit, on cancelling a picking with empty lines, will move the picking to the cancel state.

closes odoo/odoo#112417

X-original-commit: 4a4ae318
Signed-off-by: William Henrotin (whe) <whe@odoo.com>

addons/stock/models/stock_picking.py

@@ -823,6 +823,7 @@ class Picking(models.Model):
     def action_cancel(self):
         self.mapped('move_lines')._action_cancel()
         self.write({'is_locked': True})
+        self.filtered(lambda x: not x.move_lines).state = 'cancel'
         return True
 
     def _action_done(self):