Remove DCubeClient package
- Already available in ALRB (lsetup dcube). All uses of DCubeClient (ART jobs) already use that.
- Development moved to https://gitlab.cern.ch/art/dcube.
- See https://its.cern.ch/jira/browse/ATLINFR-3520 for details.
GitLab jobs artifacts no longer stored forever as of Monday, November 4th 08:30h. Further information under https://cern.ch/otg0152576