Upgrade PostgreSQLs to 12.x / 13.x

We have various PostgreSQL instances that would deserve an upgrade to PostgreSQL 12.

Considering the following issues:

• replication between belvedere and somerset lagging by several TB
• need to transfer all the data of the replica to migrate somerset to zfs
• broken replication between somerset and dbreplica0
• the indexer workers being stopped already because of the status of dbreplica0

now is probably as good a time as any to do these upgrades.

• belvedere: main
• belvedere: secondary
• belvedere: indexer
• somerset: replica (logical, from belvedere/main)
• dbreplica0: replica (physical, from somerset/replica)
• dbreplica1: replica (physical, from belvedere/indexer)

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Migrated from T2581 (view on Phabricator)