[FIX] l10n_sa_edi: adapt code with new structure of field 'display_type'

Currently, errors occur when generating the e-invoicing for
ZATCA (Saudi Arabia). This is because currently, users create invoices without
a tax, but in Saudi Arabia, the invoice line must require at least one tax.

The validation error is present at Line [1], but due to recent changes in
Code [1], the validation is not working. As a result, the user can create an
invoice line without tax.  see https://github.com/odoo/odoo/pull/130034.

This commit fixes the above issue by filtering invlocice line ids
that have display_type 'product'.

Line [1]-https://github.com/odoo/odoo/blob/d2f0a0f2c9a18a7a6cef8ca3be52324ad2a1dad6/addons/l10n_sa_edi/models/account_edi_format.py#L406


Code [1] odoo@d8d47f9#diff-78f3e1847de8ca0acf28d72a412947a549acdb08142d1dadf7646363d7972cb0R268-R280

sentry-4467808485, 4467794808

closes odoo/odoo#135737

Signed-off-by: de Wouters de Bouchout Jean-Benoît (jbw) <jbw@odoo.com>