How is the GitHub marketplace a runtime dependency? Code review, project management, build bots or whatever else should NOT affect the availability of your website.
see now you're just splitting hairs and getting into philosophy. if your website will be stale tomorrow because you can't update it today, then that is a runtime dependency imo.
Yeah, I should have clarified I was talking with my operations hat on. From a development perspective, you might call it a "deploy-time" or "scale up" dependency.
If Github being down means you're not fixing your site today, I'd call it a runtime dependency.