Reduce maxIterations of iPatFitter for track cleaning in the trigger

As part of the CPU optimisation for the muon triggers (ATR-18811), reducing the maxIterations in the iPatFitter from 15 to 4 for the track cleaning.
This reduces the MuonCombinedAlg time by 25-30% and the total chain time by 5-10% for low pT muon triggers with a very minimal impact on the muons reconstructed.