**(adapted) backport of 4c9c848f**

To reproduce the issue:
(Need stock_barcode)
1. Create a product:
    - Barcode: 1234567890123
2. Print the label
3. Try to scan the barcode and check the value read.

Error: The value is 1234567890128, the last digit is incorrect (8
instead of 3)

When printing a barcode, we use the library 'report-lab' to generate a
barcode image from a value and a barcode type. In case of EAN-13, if the
value contains a non-digit character, it will raise an error. We then
catch the error and retry to generate the barcode according to the
barcode type Code128:
https://github.com/odoo/odoo/blob/87698d90f02bfe93c6e643f4876a5ccd74788eff/odoo/addons/base/models/ir_actions_report.py#L569-L575
However, if the value contains only digits, the method will use the 12
first digits:
https://github.com/mattjmorrison/ReportLab/blob/dade0f303cb6fcdbe535c4cc92e6102c2417b699/src/reportlab/graphics/barcode/eanbc.py#L187-L188


and will then add the last one, the check digit, which is computed by
the library. This explains why, in the above use case, the barcode value
returned by the scanner is not the same than the expected one.

Note: Similar behavior with type EAN-8

OPW-2980717

closes odoo/odoo#100231

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