Identify solutions for storing DB dumps for multi-version upgrade testing

Summary

Explore solutions for storing DB dump for the latest known GitLab upgrade stop version for multi-version upgrades testing.

Details

As part of #1920 (closed), the PG dump needs to be created in MR job from UPGRADE_STOP value.

Action items

• - Explore strategy to store PG dumps for the latest known GitLab version https://docs.gitlab.com/ee/update/#upgrade-paths
  • Solutions to remove hardcoded UPGRADE_STOP
• - If separate project to be used for storing - #2355 (comment 1783504407)
  • Create a schedule to trigger new PG dump build for each new upgrade stop
  • Report pipeline results
• Use PG dumps from this unit-level to be imported to GitLab QA upgrade testing - gitlab-org/gitlab!145432 (merged)
• db:migrate:multi-version-upgrade: Silence stdou... (gitlab-org/gitlab#442778 - closed)
• Enable pipeline schedule for PG dump generator - https://gitlab.com/gitlab-org/quality/pg-dump-generator/-/pipeline_schedules

Context

This work part of the Migration testing for multi-version upgrades wi... (&19 - closed), with the goal of adding CI job which would emulate multi-version upgrades in GitLab to catch migration errors at lower level without building an environment.