Gitlab ci

https://zivgitlab.uni-muenster.de/ag-ohlberger/dune-community/dune-xt/pipelines/57198 should be the last pipeline to failing builds should upload an image to the internal docker registry: https://zivgitlab.uni-muenster.de/ag-ohlberger/dune-community/dune-xt/container_registry

This should be the first pipeline to succeed. https://zivgitlab.uni-muenster.de/ag-ohlberger/dune-community/dune-xt/pipelines/57199