[CI] Update issue comment triage workflow file

.github/workflows/issue-comment-triage.yml

@@ -10,7 +10,12 @@ jobs:
   issue_comment_triage:
     runs-on: ubuntu-latest
     env:
+      # issue_comment events are triggered by comments on issues and pull requests. Checking the
+      # value of github.event.issue.pull_request tells us whether the issue is an issue or is
+      # actually a pull request, allowing us to dynamically set the gh subcommand:
+      # https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#issue_comment-on-issues-only-or-pull-requests-only
+      COMMAND: ${{ github.event.issue.pull_request && 'pr' || 'issue' }}
       GH_TOKEN: ${{ github.token }}
     steps:
-      - name: 'Remove stale and waiting-response on comment'
-        run: gh issue edit ${{ github.event.issue.html_url }} --remove-label stale,waiting-response
+      - name: 'Remove waiting-response on comment'
+        run: gh ${{ env.COMMAND }} edit ${{ github.event.issue.html_url }} --remove-label waiting-response