A way for `exempt-issue-labels` to include [unlabelled]

[da5nsy]

Description:
exempt-issue-labels could be set so that any issues with no labels were excluded.

Justification:
The use case for this: a large project which sometimes gets behind on triaging incoming issues - it would be good if only issues which had been triaged would be eligible for being marked as stale.

Are you willing to submit a PR?
Abstractly, yes, in practice, I probably don't have the necessary skills/knowledge for this particular one.

[v-priyagupta108]

Hi @da5nsy 👋,
Thank you for the feature request. We will investigate it and get back to you as soon as we have some feedback.

[rcomer]

In the meantime, could you set up your issue template to automatically add a "needs triage" label on opening (as is used in this repo) and make that the exempt label?

[da5nsy]

Thanks @rcomer, that's a great suggestion, and I've suggested it to the maintainers of the repo which made me think of this.

The limitation is that this wouldn't apply for issues which are already open, although I guess one could go through all of the open un-triaged issues and add this label.