Use the registry rather than artifacts for storing images

This fixes the failing master pipeline

• Pipelines were failing because the images are being passed between jobs as artifacts, and the size of the image is larger than allowed for the shared runners
• artifacts were used rather than the registry originally because artifacts had a working retetion and cleanup. This is now also the same for the container registry, so we can use that.
• I've turned on registry cleanup for the container registry. It currently keeps the 5 latest tags per image, keeps anything labelled latest, and keeps anything built within the last 30 days, but removes anything else