Update sim sending letter template with correos SIM delivery
CHANGELOG:
### Changed
- [#973](https://git.coopdevs.org/coopdevs/som-connexio/odoo-somconnexio/-/merge_requests/973) Update sim sending letter template with correos SIM delivery
Related card: https://trello.com/c/55isvNo0/1540-actualitzar-la-carta-amb-lenviament-de-sim-per-correus
Edited by Gerard Funosas