Generate a new set of regression data

Occasionally we make changes to the regtest files in ways that are not okify-able. e.g., due to file structure / metadata changes that make the existing truth files inconsistent with code expectations. It's nice to be able to regenerate all regression test truth data from scratch in these cases. There are scripts in romanisim (generate uncal files) and romancal make_regtest.sh github action to do this "make from scratch" task.

There is also a github action to run these for you, saving the need to download a lot of files from artifactory

The pattern is:

• Make changes to romancal / rdm / rad / romanisim for a certain task on branches on your forks
• Run romancal_regtest_gen Github Action, pointing to appropriate new branches of romancal / rdm / rad / romanisim, and setting the new artifactory environment to create to something descriptive, e.g., dev-skycell-regtest
• Wait for the generator to finish (1 hr). This generates the files in a new environment and saves them on Artifactory under roman-pipeline/, e.g. roman-pipeline/dev-skycell-regtest
• Run regression tests against the new artifactory environment (setting the artifactory environment to the new thing we created; in this example, dev-skycell-regtest
• Link to successful regtest in PR
• On merge, move the old roman-pipeline/dev directory to a backup directory, and move the new test directory to dev