hosts: db0: Promote to primary

All data have been migrated from the PostgreSQL server in Kubernetes and
the three applications that used it (Firefly-III, Authelia, and Home
Assistant) have been updated to point to the new server.

To avoid comingling the backups from the old server with those from the
new server, we're reconfiguring WAL-G to push and pull from a new S3
prefix.

host_vars/db0.pyrocufflink.blue.yml

@@ -1 +0,0 @@
-postgresql_standby: true