Do not add `needs-further-triage` when `untriaged` label exists

[jeffhandley]

When the needs-author-action label is in place and the author comments on the issue, we have a step of automation that replaces the needs-author-action label with the needs-further-triage label. As reported by @ManickaP, this does not take the untriaged label into account, and it can result in both untriaged and needs-further-triage being applied, which is unexpected (and noisy).

I believe the expected behavior would be:

If the needs-author-action label is applied and the author comments:

• If the untriaged label is applied, simply remove the needs-author-action label
• If the untriaged label is not applied, remove the needs-author-action label and add the needs-further-triage label

@ManickaP and @eiriktsarpalis -- do you both agree with those conditions?

[eiriktsarpalis]

Sounds reasonable to me 👍