GH Actions/label mngmnt: auto-remove merge conflict label on PR merge

... as a PR wouldn't have been merged if the merge conflict still existed.

(Adding the "merge conflict" labels works really well, but they don't always seem to get removed quickly enough)

Author: jrfnl

.github/workflows/label-remove-outdated.yml

@@ -39,6 +39,7 @@ jobs:
           labels: |
             Status: awaiting feedback
             Status: close candidate
+            Status: has merge conflict
             Status: needs investigation
             Status: triage