Switch all builds to kaniko and discontinue docker-dind
We already use kaniko for somethings. We only introduced docker-dind to simplify the cloud migration; it was never intended to be the end. It occasionally causes problems and is unsafe.
This also applies to https://gitlab.mpcdf.mpg.de/nomad-lab/nomad-lab-homepage This also applies to https://gitlab.mpcdf.mpg.de/nomad-lab/nomad-gui