gaudi_add_pytest duplicates tests
!1440 (merged) was applied in lhcb/LHCb!4059 (merged) which triggered the observation that tests are duplicated.
See for example https://lhcb-nightlies.web.cern.ch/nightly/lhcb-master-mr/8732/LHCb/x86_64_v2-centos7-clang12-opt/tests#PyConf_pytest_python_PyConf