CNG: Upgrade PostgreSQL 12 (libraries/client)
Summary
Upgrade PostgreSQL libraries / client in CNG images to PG12 stable version.
Details
From #852 comments:
During the @gitlab-org/distribution
maintainers call this week, we've postulated that we can safely package and "pre-upgrade" the contained PostgreSQL tools / libraries to "near if not latest" publicly available versions.
- Generally speaking, PG12 can speak to PG backwards to around 7. We (GitLab) currently require PG10, with incoming requirement of PG11 sometime after %13.0. We are within 3 major versions and thus unlikely to have a sudden breakage.
- Since the client protocol rarely changes, and when it does, it is loudly & widely communicated, we shouldn't have too many concerns about breaking backwards compatibility.