Move from lib/pq to jackc/pgx for the PostgreSQL driver
lib/pq
is no longer actively maintained (see the notice in
https://github.com/lib/pq#status) and the recommended driver, both by
the lib/pq
maintainer and the GitLab Go guidelines (see
https://docs.gitlab.com/ee/development/go_guide/#orm) is now jackc/pgx
.