Build and store container images
We currently use upstream Bookworm images in GitLab CI builds, which implies time spent for installing dependencies, which impacts development experience and delays deployment.
To improve those, we need to solve different problems:
- Our GitLab Runner doesn't have the privileges needed to build containers.
- We don't have a (canonical and secure) registry to store images (related: #17840).
There are different ways the above can be solved and the security implications of each need to be assessed.