Remove remaining usage of UT

Cherry-picked from !393 (merged)

UT is not supported on 2018-patches branch.

To be backported also to lhcb-stripping24r2-28r2-patches 2017-patches 2016-patches reco15-patches, digi14-patches, hlt2016-patches

added all-slots cleanup labels

• [2019-12-21 00:07] Validation started with lhcb-2018-patches#796

removed all-slots label

merged

mentioned in commit 4c79fe0d

mentioned in commit 8e0b8c4b

mentioned in merge request !396 (merged)

mentioned in commit 4095a6b7

mentioned in merge request !397 (merged)

mentioned in merge request !417 (merged)