The following trick used to work, because `sudo()` was actually making
an environment for the superuser to operate upon:
request.env[...].sudo().method(...)
It no longer works in general, since `sudo()` now makes an environment
in superuser mode but with `uid=None`! It may still work by accident
for operations that never use `env.uid`, but is broken in general.
Using `auth='public'` fixes the problem by using the public user when no
user is available.
closesodoo/odoo#34297
Signed-off-by: Olivier Dony (odo) <odo@openerp.com>