JSON Schema $ref use issue

[Relequestual]

I raised this same issue at GSA/project-open-data-dashboard#366 but thought it might be worth cross referencing, as you seem to use the same JSON Schemas for validation.

Regarding the catalogue schema...

The JSON Schema uses "draft-04".
In draft-04, when $ref is used, all other keywords MUST ("SHALL") be ignored.

https://datatracker.ietf.org/doc/html/draft-pbryan-zyp-json-ref-03#section-3

Any members other than "$ref" in a JSON Reference object SHALL be
ignored.

We (JSON Schema) later bundled the separate JSON Ref specification into the JSON Schema specification.

As of draft 2019-09, $ref can be used alongside other keywords without this adverse effect, however this schema and many others in this repo use draft-04, and so may have instances validate successfully unexpectidly.