[Task] Build Firmware-Toolchain

Create docker container(s) (externally to this repository) for building the firmware for ARM devices. Our work in the magic-wand/firmware project might be a good start:

• https://gitlab.ring-0.net/magic-wand/firmware/-/blob/devel/docker/build.dockerfile
• https://gitlab.ring-0.net/magic-wand/firmware/-/blob/devel/.gitlab-ci.yml#L9
• https://gitlab.ring-0.net/magic-wand/firmware/container_registry/9