[FIX] stock: display lot on delivery slip

When consulting a delivery slip, a portal user won't see the lots/serial
numbers used.

To reproduce the error:
(Need demo data)
1. Create a product P
    - Product Type: Storable
    - Tracking: By Lots
2. Update its quantity
3. In Settings, enable "Display Lots & Serial Numbers on Delivery Slips"
4. Create + Validate a SO:
    - Customer: Joel Willis
    - Lines: 1 x P
5. Validate the delivery
6. Log in DB with 'portal' (Joel Willis)
7. On SO, open the Delivery Slip

Error: The product's lot is not mentioned

Here is the condition to display the lot:
https://github.com/odoo/odoo/blob/c61db20204700a375f7005f50f95b44a60c3bb70/addons/stock/report/report_deliveryslip.xml#L77-L79

Problem is that portal users are not part of
`group_lot_on_delivery_slip`

When enabling the option, the groups are updated here
https://github.com/odoo/odoo/blob/adccb562209c2431a49438d36794f0765f1bc86d/odoo/addons/base/models/res_config.py#L570-L576
`implied_group` (which is `stock.group_lot_on_delivery_slip` in our
case) is added to `groups.implied_group`
The variable `groups` comes from `classified`, which is defined thanks
to method `_get_classified_fields` (see L553 in above code block)
And here is an extract of how this method works:
https://github.com/odoo/odoo/blob/adccb562209c2431a49438d36794f0765f1bc86d/odoo/addons/base/models/res_config.py#L460-L462
At some point, it checks if the field `group_lot_on_delivery_slip` has
an attribute `group`. In case `group` is not defined, the group
`base.group_user` is used. This is the reason why, by default, the
option is enabled for internal users only instead of all users.
Therefore, we just need to define the attribute `group` to the field
`group_lot_on_delivery_slip`

OPW-2558761

closes odoo/odoo#72656

X-original-commit: 475b35397b7254012a082a1206c478084c069857
Signed-off-by: William Henrotin <Whenrow@users.noreply.github.com>
Signed-off-by: Adrien Widart <adwid@users.noreply.github.com>

addons/stock/models/res_config_settings.py

@@ -13,7 +13,7 @@ class ResConfigSettings(models.TransientModel):
     group_stock_production_lot = fields.Boolean("Lots & Serial Numbers",
         implied_group='stock.group_production_lot')
     group_lot_on_delivery_slip = fields.Boolean("Display Lots & Serial Numbers on Delivery Slips",
-        implied_group='stock.group_lot_on_delivery_slip')
+        implied_group='stock.group_lot_on_delivery_slip', group="base.group_user,base.group_portal")
     group_stock_tracking_lot = fields.Boolean("Packages",
         implied_group='stock.group_tracking_lot')
     group_stock_tracking_owner = fields.Boolean("Consignment",