chore(deps): bump tibdex/github-app-token from 1.8.2 to 2.0.0 (#4556)

Bumps [tibdex/github-app-token](https://github.com/tibdex/github-app-token) from 1.8.2 to 2.0.0.
- [Release notes](https://github.com/tibdex/github-app-token/releases)
- [Commits](0d49dd7211...0914d50df7)

---
updated-dependencies:
- dependency-name: tibdex/github-app-token
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/backport.yaml

@@ -14,7 +14,7 @@ jobs:
     steps:
       - name: Generate token
         id: generate_token
-        uses: tibdex/github-app-token@0d49dd721133f900ebd5e0dff2810704e8defbc6
+        uses: tibdex/github-app-token@0914d50df753bbc42180d982a6550f195390069f
         with:
           app_id: ${{ secrets.BACKPORT_APP_APPID }}
           private_key: ${{ secrets.BACKPORT_APP_PRIVATE_KEY }}