As far as I can tell, if we're using schemathesis this repo could be replaced by a single-line CLI invocation:
st run --experimental=openapi-3.1 --checks all --base-url http://localhost:8000 https://raw.githubusercontent.com/stapi-spec/stapi-spec/refs/heads/main/openapi.yaml
Is the intent to expand validation beyond schemathesis, ala https://github.com/stac-utils/stac-api-validator? If so, my recommendation would be to remove schemathesis and just point people to that simple invocation.
I bring this up because I was working on a refactor of this repo in preparation for the STAPI sprint, and using schemathesis directly doesn't seem to get us much of a win above and beyond the schemathesis CLI.