Investigate upgrading Debian base to 12 Bookworm (from 11 Bullseye)

Summary

Investigate feasibility of upgrading the base image / repository on which we base the primary images from Debian 11 to Debian 12.

It was initially released as version 12.0 on June 10th, 2023 and its latest update, version 12.1, was released on July 22nd, 2023.

Details

Ideally, where till be little to no impact, but we should confirm this. Package names may have changed, and possibly dependencies available within the default -slim image on which we base.

1. Attempt naive swap
2. Update any dependencies that have had package name changes
3. Complete full QA suite within gitlab-org/charts/gitlab