We have a lot of tests that use the SL7 singularity container. These need to use the EL9 one instead.

Examples are:

https://github.com/fermitools/jobsub_lite/blob/master/tests/dagnabbit/dagTestH
https://github.com/fermitools/jobsub_lite/blob/master/scripts/xmas_plain
https://github.com/fermitools/jobsub_lite/blob/master/tests/dagnabbit/dagTestHS
https://github.com/fermitools/jobsub_lite/blob/master/tests/data/condor_submit_dag/dagbegin.cmd
https://github.com/fermitools/jobsub_lite/blob/master/tests/data/condor_submit_dag/dagend.cmd
https://github.com/fermitools/jobsub_lite/blob/master/tests/data/condor_submit_dag/simple.cmd