[FIX] Ignore sale order lines without product_id

In some conditions, such as the use case shown on:
https://github.com/guewen/odoo-reproduce-issues/blob/compute-qty-at-date/compute_qty_at_date/models/sale_order_line.py

The order of the computations can make that we have a line without
product_id (we come from an onchange because we removed the product form
the line), but 'display_qty_widget' is not yet recomputed.

Not checking if we have a product_id means we can end up with
'grouped_lines' that contains an entry for the line, but then
'product_qties' does not contain the product the dict comprehension
that builds the dictionary 'qties_per_product' fails with a KeyError.

opw-2273768

closes odoo/odoo#56406

X-original-commit: 9060b347949d11880c554468f551d25e874590d1
Signed-off-by: Simon Goffin (sig) <sig@openerp.com>

addons/sale_stock/models/sale_order.py

@@ -299,7 +299,7 @@ class SaleOrderLine(models.Model):
         # We first loop over the SO lines to group them by warehouse and schedule
         # date in order to batch the read of the quantities computed field.
         for line in self:
-            if not line.display_qty_widget:
+            if not (line.product_id and line.display_qty_widget):
                 continue
             if line.order_id.commitment_date:
                 date = line.order_id.commitment_date