Whether at db initialization or upgrade time.
This step is actually done "systematically" manually by sysadm after an initialization or an upgrade.
That way, sysadm won't have to be reminded to do it if they missed the step (I sometimes do forget it).
This also enhances the pytest-plugin to initialize the schema table with the role guest.
Which is a defacto standard existing role in all swh dbs. Tests for the cli are using again
the pytest-plugin db tool (i think it got removed at some point for some reason).
Related to T4228