🚸(apps) run the db_migrate job before starting application pods

[sampaccoud]

Purpose

If we run db_migrate after starting the new pod:

• the current pod has to be compatible with the state of the db before and after the migration.
• the new pod has to be compatible with the state of the database before and after a migration. This is not possible for a new database, and not easy for schema updates.

If we run db_migrate before starting a new pod, the new pod only has to be
compatible with the state of the database after the migration.

Proposal

Tag all db_migrate jobs as pre jobs.