Development for LHC@home

ATLAS native 1.20 was just released which uses apptainer instead of singularity. At the moment apptainer functionality is identical to singularity. If apptainer does not work there is still a fallback to using singularity so tasks should work as normal for those who have a locally installed singularity. But this will be removed at some point in the future so we recommend that people who cannot use singularity/apptainer from CVMFS install a local version of apptainer instead of singularity. apptainer provides a backwards compatible "singularity" command so installing it will not break production tasks still relying on singularity.

I made a silly mistake when releasing this version by forgetting to make the wrapper script executable so all tasks were failing. Version 1.21 fixes this.