mexomg_0008 had no changes except 1) dataset.cat replaced "first"
with the correct "seventh" extension, and 2) release.cat had release
info. So I'll just ingest dataset.cat into EN's PDS3 database and
replace the previous ingestion's (202004-mex/) dataset.cat with this
and delete and reingest.  I'll use release.cat's info on the 
SS-20211130.shtml web page.

mrosh_2101 had no changes whatsoever in its catalog files.