Merged
requested to merge atlas-physics/pmg/mcexperts/powheg-experts/athena:21.6-PowhegControl-FixAnotherMadSpinIssue into 21.6
This MR fixes the issue with MadSpin decays in PowhegControl encoutered after update to MadGraph5-2.9.9.atlas2 in AthGeneration,21.6.91. Instead of executing the madspin python executable directly, we call it using the python executable to avoid issues with the shebang which now calls for python3 explicitely.