Remove PID Tunings from FlavourTagging

@dohanlon @mschille @vchobano This fix is related to MR DaVinci!372 (closed) and is caused by Rec!1894 (merged). Run 2 PID tunings have been removed for Run 3 and it has been decided to replace tuned input PID variables with their "untuned" counterpart in Phys/FlavourTagging for now.