[FIX] l10n_eu_service: add new LU tax mappings

Taxes in Luxembourg have been reduced until the end of 2023: 17% -> 16%, 14% -> 13% and 8% to 7%.

This change remaps the OSS tax mappings for Luxembourg to the new tax rates.

task-3159138

closes odoo/odoo#111234

Signed-off-by: Josse Colpaert <jco@odoo.com>