The "unlabeled" action trigger on PRs creates spurious workflow approvals

[ambv]

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Bug

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Hi there, I'm from the Python organization here on GitHub.
Recently, we had to switch back to "Require approvals for first-time contributors" (from the previously used "... who are new to GitHub" due to CI spam:

When we did that, one of our GitHub apps, "bedevere", started triggering workflow approvals as if the bot was "a new contributor":

However, in the above screenshot you can see how the workflow approval only happens for the "unlabeled" trigger.

More screenshots

The "unlabeled" trigger causes an "Approve and run" button to appear on the PR.

The "labeled" trigger does not cause this and the check runs fine.

The workflow file lists both triggers in the same list, there should be no difference between them.

Expected behavior

Bots should not be treated as "new contributors", and therefore should never trigger "Approve and run". And even if they did, all triggers should behave the same. And if we approve the run and land a PR, that bot should no longer be treated as a "new contributor".

This is somewhat disruptive to Python as the bots are our automation that acts on every single PR. We would rather not have to switch back to "... who are new to GitHub" due to CI spam issues while we are already backed up on CI resources.

Please advise 😇