possible bug that doesn't update PR comment and coverage on force push with no new commits

[shahzadlone]

I have noticed my current head always differs on force pushes (after rebase) on PRs that don't introduce new commits.

Here is an example from https://github.com/sourcenetwork/defradb/pull/1414:

Moreover: We open-sourced and have since removed the codecov token (and noticed that uploading reports started failing and became flaky without the token). Wonder if that is related to this bug described above as well.

Maybe related: https://community.codecov.com/t/force-push-intermittently-leads-to-codecov-not-updating-pr/68