Prevent 'commit' dictionary in a stack-based workflow tck
https://gitlab.cern.ch/lhcb/tck-specs/-/jobs/41341825 test run Failed correctly (i.e. workflow='stack-based' but 'commits' is defined in tck.)
https://gitlab.cern.ch/lhcb/tck-specs/-/jobs/41341987 remains green back to usual
Edited by Luke Grazette