Ignore unchecked status codes

Port to run2-patches of !1972 (merged)

As a reminder, some of the unchecked StatusCodes must be checked, but this change has the benefit of preserving the old behaviour.

See gaudi/Gaudi!763 (merged)

added Build all-slots workaround labels

• [2020-03-10 00:06] Validation started with lhcb-run2-patches-dev4#261
• [2020-03-10 00:08] Validation started with lhcb-run2-patches#683
• [2020-03-10 13:50] Validation started with lhcb-run2-patches#684
• [2020-03-10 15:52] Validation started with lhcb-run2-patches#685
• [2020-03-11 00:08] Validation started with lhcb-run2-patches-dev4#262
• [2020-03-11 00:10] Validation started with lhcb-run2-patches#686
• [2020-03-12 00:12] Validation started with lhcb-run2-patches-dev4#263
• [2020-03-12 00:16] Validation started with lhcb-run2-patches#687
• [2020-03-13 00:11] Validation started with lhcb-run2-patches#688
• [2020-03-13 00:14] Validation started with lhcb-run2-patches-dev4#264

mentioned in merge request Brunel!973 (merged)

removed all-slots label

mentioned in commit b33f253d

merged

mentioned in commit Brunel@838f70bc