Fix older AthenaMP digitization ART jobs (ATLASSIM-5641)
Some older Digitization ART jobs are using conditions tags which do not include the /TRT/Calib/PID_NN
folder. This isn't needed in digitization itself, but a dependency seems to get picked up by the RDOMerging step. Most likely due to some lax configuration somewhere. This MR adds the required overrides to allow the RDO merging steps to run. These tests will be dropped soon anyway.
(As this MR only contains changes to ART scripts, the CI pipeline result will not be influenced in any way.)