Currently, meas_mosaic uses its own persistence format for its calculations of new catalog values, etc. From
DM-10007, meas_mosaic now persists an afw.image.PhotoCalib containing the same model. We should switch to using that persistence format for the catalog updates, to make the switch to jointcal more trivial.
Once done, we can more reliably confirm that the changes in
DM-11905 did not affect meas_mosaic's PhotoCalib persistence by regenerating the files in the tests/data// directory (I had manually hacked them to work for the ticket itself) and re-running tests/test_FluxFitBoundedField.py.