ci: Delete nightly build artefact after testing the container
ci: Delete nightly build artefact after testing the container

Leave the artefact until after the container has been built and tested.
In case the test fails the artefact can be still downloaded to analyse
what might have caused the container build or test to fail.

gitblit/gitblit,gitblit/gitblit,gitblit/gitblit,gitblit/gitblit,gitblit/gitblit