Use GitHub App token in backport workflow to trigger CI

.github/workflows/backport.yml

@@ -13,24 +13,28 @@ jobs:
     runs-on: ubuntu-latest
 
     # Only run when pull request is merged
-    # or when a comment starting with `/cherry-pick` is created by someone other than the
-    # https://github.com/backport-action bot user (user id: 97796249). Note that if you use your
-    # own PAT as `github_token`, that you should replace this id with yours.
+    # or when a comment starting with `/cherry-pick` is created by someone other than the CI bot
     if: >
       (
         github.event_name == 'pull_request_target' &&
         github.event.pull_request.merged
       ) || (
         github.event_name == 'issue_comment' &&
         github.event.issue.pull_request &&
-        github.event.comment.user.id != 97796249 &&
+        github.event.comment.user.id != 278318962 &&
         startsWith(github.event.comment.body, '/cherry-pick')
       )
     steps:
+      - uses: actions/create-github-app-token@v1
+        id: app-token
+        with:
+          app-id: ${{ vars.CI_APP_ID }}
+          private-key: ${{ secrets.CI_APP_KEY }}
       - uses: actions/checkout@v4
       - name: Create backport pull requests
         uses: korthout/backport-action@v4
         with:
+          github_token: ${{ steps.app-token.outputs.token }}
           add_author_as_assignee: true
           auto_merge_method: "squash"
           pull_title: "[${target_branch}] ${pull_title}"