[CI] Make debug-mode tests mandatory again
Use the debug-mode test labels introduced in https://zivgitlab.uni-muenster.de/HPC2SE-Project/pacxx-samples/merge_requests/18
Edited by Jö Fahlke
Use the debug-mode test labels introduced in https://zivgitlab.uni-muenster.de/HPC2SE-Project/pacxx-samples/merge_requests/18