MCRecoTruth: quasi-stable particles may be matched to reconstructed tracks

While testing fixes for issues seen in ATLPHYSVAL-1154, I observed multiple warnings of this form:

egammaTruthAssociation.MCTruthClassifier               1     0 WARNING track matched to the truth with status 2

When quasi-stable particle simulation is enabled (as it is by default for MC23), then some status 2 particles are propagated through the detector by Geant4, so it is possible that a reconstructed track is matched to one of these particles. I think that we can downgrade the warning to a debug message in this case. The AOD file will remain unchanged.