Disable wait-for-build when Github auto-merge is enabled #3887

Github has a new (beta) feature that solves the same problem as wait-for-build but doesn't require the tab to stay open, it also respects other merge rules. See here: https://docs.github.com/en/free-pro-team@latest/github/collaborating-with-issues-and-pull-requests/automatically-merging-a-pull-request

The Refined Github wait-for-build UI should be hidden when this feature is enabled. The current UI (below) is a little confusing.