chore(deps): bump tibdex/github-app-token from 1.7.0 to 1.8.0 (#3922)

Bumps [tibdex/github-app-token](https://github.com/tibdex/github-app-token) from 1.7.0 to 1.8.0.
- [Release notes](https://github.com/tibdex/github-app-token/releases)
- [Commits](021a2405c7...b62528385c)

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

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@021a2405c7f990db57f5eae5397423dcc554159c
+        uses: tibdex/github-app-token@b62528385c34dbc9f38e5f4225ac829252d1ea92
         with:
           app_id: ${{ secrets.BACKPORT_APP_APPID }}
           private_key: ${{ secrets.BACKPORT_APP_PRIVATE_KEY }}