[TrigValTools] Add ignore pattern to rootcomp.py for HltEventLoopMgr/PopScheduler
The two histograms:
HLTFramework/HltEventLoopMgr/PopSchedulerNumEvt
HLTFramework/HltEventLoopMgr/PopSchedulerTime
added in !44977 (merged) depend on timings between threads and thus are never exactly reproducible. Add them to the ignore patters of the rootcomp.py
script.
Fixes ATR-23710 and probably also a secondary failure that would be seen in ATR-23978 if the histogram was in the reference.
MR submitted from GitLab Web Editor, so the branch is on the main repo.