standardize env var for DETECTOR_PATH

benchmarks/clustering/full_cal_clusters.sh

benchmarks/clustering/options/full_cal_clusters.py

benchmarks/clustering/options/full_cal_digi.py

benchmarks/ecal/emcal_electrons.sh

benchmarks/ecal/emcal_pi0s.sh

benchmarks/ecal/full_emcal_electrons.sh

benchmarks/ecal/options/crystal_calorimeter_reco.py

benchmarks/ecal/run_emcal_barrel_electrons.sh

benchmarks/ecal/run_emcal_barrel_pions.sh

benchmarks/imaging_shower_ML/sim_rec_tag.py

benchmarks/tracking/options/tracker_reconstruction.py

options/tracker_reconstruction.py