remove Powheg diboson 603769-603771 useless lines
Description of bug
Remove the useless lines as suggested in https://its.cern.ch/jira/browse/ATLMCPROD-11233 -> There is no need to specify the scale variations (in principle also not the PDF ones, but I understand you want PDF4LHC21 on the 0th weight position) ->The last part can be just: genSeq.Pythia8.Commands += ['Powheg:NFinal = 2']
Changes introduced
Tests
Issues resolved
Closes #