Refresh container-image builder.
This updates the builder to have some improvements that I've carried over from a previous location:
.gitlab-ci.yml:
- change to a template to build multiple suites easier
- switch to debain:bookworm for the image, as latest is variable (I would switch this to our own pre-built after it is available)
- incorporate bootstrap phase into template, so multiple different templates with different tools are possible
- tag and push to registry existing container with _previous suffix, for roll-back possibilities
- add rules that will build on changes
- implement templates for bullseye, bookworm and bullseye-backports
debian-builder.sh:
- set -x to fail early
- set non-interactive ode to apt, so it doesn't get stuck
- allow for the default apt sources to be enabled
- add functionality to optionally $ADD_MIRROR
- add functionality to pass $SUITE
- removed EPOCH date info, seems it needs more work to be useful
- cleaned up the dpkgopt path-exclude options on discussion after discussion with the mmdebstrap maintainer
- push the container to the registry