New HV from Carlo Oleari

[covarell]

All HV, HVJ and HVJ_ew processes again operational in CMSSW13 (from Carlo Oleari).

Very important for all Run3 VH NLO and MiNLO productions.

@agrohsje @jshin96 @yihui-lai @mlizzo

[lviliani]

Thank you @covarell !
I see you have also edited the b_bbar_4l part in helpers.py.
Is it also related to the update from Powheg authors?

[covarell]

Yes, since this is using OpenLoops2 now, the old patch does not apply anymore (same for all VH processes)