Change Details

Previously, `let-else` wasn't formatted at all, because the formatter didn't support it. Users trying to push code with the latest formatter will have arcanist complain, so we format the code.

Previously, `let-else` wasn't formatted at all, because the formatter didn't support it. Users trying to push code with the latest formatter will have arcanist complain, so we format the code and update the CI to the latest nightly version.

Previously, `let-else` wasn't formatted at all, because the formatter didn't support it. Users trying to push code with the latest formatter will have arcanist complain, so we format the code and update the CI to the latest nightly version.