Sweeping !39426 from 21.2 to master. AnalysisTop: Implementation of anti-muon shape systematics - ANALYSISTO-1044

Atlas Nightlybuildrequested to merge
cherry-pick-7226bab72c2-master into master

AnalysisTop: Implementation of anti-muon shape systematics - ANALYSISTO-1044

See merge request !39426 (merged)

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