Remove xenv references

benchmarks/clustering/full_cal_clusters.sh

benchmarks/ecal/run_emcal_benchmarks.py

benchmarks/far_forward/far_forward_protons.sh

benchmarks/imaging_ecal/run_emcal_barrel.sh

benchmarks/imaging_ecal/run_emcal_barrel_pion_rej.sh

benchmarks/imaging_ecal/run_imcal_pion0.sh

benchmarks/imaging_shower_ML/sim_rec_tag.py

benchmarks/rich/forward_hadrons.sh

benchmarks/track_finding/multiple_tracks.sh

benchmarks/track_fitting/single_tracks.sh

benchmarks/tracking/central_pions.sh