The rake task gitlab:backup:create doesn't consider the multi-database setup

When running the rake task gitlab:backup:create

The output looks like this

2022-06-03 20:00:30 +0200 -- Dumping database ... 
Dumping PostgreSQL database gitlabhq_development ... [DONE]
2022-06-03 20:00:31 +0200 -- Dumping database ... done

Even if I have the newly decomposed DB setup config/database.yml

  main:
    database: gitlabhq_development
    host: /Users/omar/gdk/postgresql
  ci:
    database: gitlabhq_development_ci
    host: /Users/omar/gdk/postgresql

with two databases.

It should take the 2nd CI database into consideration.

Additionally, this CI job: .gitlab/ci/rails.gitlab-ci.yml:db:backup_and_restore: should be updated to work in a decomposed pipeline so we have automated checking for this functionality.