Make lb-ci deploy structure remove inactive projects
Useful to save some time in /ci-test jobs by avoiding packaging and deploying disabled projects.
Comparing https://lhcb-nightlies.web.cern.ch/nightly/lhcb-master-mr/12364/ and https://lhcb-nightlies.web.cern.ch/nightly/lhcb-master-mr/12366/ (same build, but checkout with or without this MR), we didn't save much time in the checkout, because most of the time is spent checking out the projects, but we saves 300MB in artifacts on EOS.
It's not much, but it might be worth it.