Modify the action workflow so that it fails on errors

[katilp]

The current action workflow does not fail on compilation errors or on cmsRun job exceptions, e.g.:

• https://github.com/cms-legacydata-analyses/PhysObjectExtractorTool/runs/2969661153?check_suite_focus=true#step:4:121
• https://github.com/cms-legacydata-analyses/PhysObjectExtractorTool/runs/2969661153?check_suite_focus=true#step:4:140

Add a check on errors to the command.sh script (or else, where needed)

[katilp]

Add set -e to command.sh