Swim test bugs

[benjamin-shen]

On prod, trying to remove "Swim Test" (Transfer Credits) from the side bar doesn't do anything. It should change it from "yes" to "no" in onboarding.

On staging (with the double graph approach), there is a course card warning if the safe requirements graph doesn't include an edge from the course to at least one requirement. This impacts swim test because it's not in the graphs at all.