Sweep TriggerMenuXML fixes from 21.0 to 21.0-mc16a
This is a manual sweep of https://gitlab.cern.ch/atlas/athenaprivate1/-/merge_requests/633 and https://gitlab.cern.ch/atlas/athenaprivate1/-/merge_requests/811 from 21.0 to 21.0-TrigMC.
Fixes ATR-22237