Dev: Run clj-kondo --lint in CI

[rads]

I noticed CI was passing in my PR despite having an unused require. Usually IntelliJ catches this for me (there's a plugin for clj-kondo integration) but for some reason Cursive is getting errors in this project and my usual editor linting is not working.

Do we want to block on clj-kondo --lint in GitHub Actions so we can catch these issues before merging to main?

[borkdude]

Sounds good to me. I think the setup-clojure action also has clj-kondo.