Reference sim 1.2_zenith changes

[jpober]

New versions of reference sim 1.2_zenith (regardless of beam) do not match the old ones (regardless of which Google Drive link). There are two source catalogs that could be used for this reference sim in the repo, too, but neither give visibilities that match the Google Drive either.

Detailed description here: https://www.overleaf.com/9613713963jthpjznmmyvx