Thanks for raising this. I have opened Bug #30919: sync_task fails with `The Dynflow world was not initialized yet.` in rake tasks on nightly production - Katello - Foreman to track this.
In the mean time, could you try adding
katello:pulp3_post_migration_check
to
self.rake_tasks_with_executor = … list
in
/opt/theforeman/tfm/root/usr/share/gems/gems/dynflow-1.4.6/lib/dynflow/rails/configuration.rb and re-running foreman-rake katello:pulp3_post_migration_check