CP Algorithms: Fix MC20a warnings for muon trigger SFs
Following the update in !76672 (merged), the type of the years
parameter changed, preventing the MC20a single-year trigger check being fixed here from ever succeeding. This produces numerous warnings of the form
MuonTrigEfficiencyCorr...WARNING Could not find what you are looking for in the efficiency map. The trigger you are looking for, year and mc are not consistent, or the trigger is unavailable in this data period. Returning efficiency = 0.
which are removed with this fix.
/cc @tadej