Bump version 12.0.2.1.8

CHANGELOG:

## [12.0.2.1.8] - 2023-03-13
### Changed
- [#979](https://git.coopdevs.org/coopdevs/som-connexio/odoo-somconnexio/-/merge_requests/979) Allow to create contracts without "vodafone_contract_code"
- [#970](https://git.coopdevs.org/coopdevs/som-connexio/odoo-somconnexio/-/merge_requests/970) Mail Activity Type diversification

### Fixed
- [#996](https://git.coopdevs.org/coopdevs/som-connexio/odoo-somconnexio/-/merge_requests/996) feat: add 02 as previous provider
- [#991](https://git.coopdevs.org/coopdevs/som-connexio/odoo-somconnexio/-/merge_requests/991) Fix change holder wizard. Pack fiber only if new mobile contract product is pack exclusive.
- [#977](https://git.coopdevs.org/coopdevs/som-connexio/odoo-somconnexio/-/merge_requests/977) Fix Address Change process in contracts in pack
- [#886](https://gitlab.com/coopdevs/odoo-somconnexio/-/merge_requests/886) Normalize the uses of VAT

Related card: https://trello.com/c/oE5BRIZb/693-release-120218

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