[hotfix] Query.yield_per() method is not compatible subqueryload eager loading

https://push-notifications-sentry.web.cern.ch/sentry/jobs-qa/issues/1000

The yield_per Query option is currently not compatible with joined collection eager loading. Please specify lazyload('*') or query.enable_eagerloads(False) in order to proceed with query.yield_per().

On /app/notifications_jobs/jobs/archive/archiver.py in process_channels at line 23