Only exclude PRs with linked issues in the same repo

[wagoodman]

What happened:
On PR anchore/syft#3348 , this is linked to an issue in another repo, which means we'll filter out the PR but we should not have done this since it's an issue that will not be in the issue list.

What you expected to happen:
Since we can't find the issue in the same repo we keep the PR as evidence in the changelog

Open question: since this also had bug as a label on the PR shouldn't this have been included anyway? That is, shouldn't this have overridden the issue link?