Steps to reproduce:
- set shipping methods country to mexico (empty states)
- fill an order on website on check out select seprate shipping/billing
- on billing set country as US
- on shipping the only country avialable is mexico
- avialable states are the ones from the US not mexico

Bug:
the states are set from the country of the customer even though it isn't
an option on any carrier.
bug was introduced by this commit[1]

Fix:
revert the mentioned commit(1) since a new commit[2] was introduced that
correctly handles that use case too

[1]:https://github.com/odoo/odoo/commit/d59fe9c58c2dcc2bf6613adb7ac3662597b50496
[2]:https://github.com/odoo/odoo/commit/297641da69982d6c76bd591296636b479cabf657



opw-3230361

closes odoo/odoo#126054

Signed-off-by: William Henrotin (whe) <whe@odoo.com>