Steps to reproduce bug:
- Create a label, for example "old"
- Assign that label to a PR
- Search for PRs that do not contain that label, for example, "is:merged -label:old". The PR should not show up.
- Rename the label, for example "old"->"new".
- Search for PRs that do not contain the renamed label, for example, "is:merged -label:new".
Expected: The PR should not show up because it has the new label.
Actual: The PR shows up in the search!