Jenkinsfile tweaks: No ubuntu cuda test, lock cvmfs deploy

• We don't have ubuntu gpu machine, so the ubuntu dev4cuda tests were running on centos7, failing to actually run anything, so we can just ignore those
• The cvmfs install step always looks very long, I hope by adding a lock we can see the actual run time and maybe see those stacks that take the longest and realise we need to add install latest for them or something