try to give permissions to change workflow files 4

Author: JanFSchulte

.github/workflows/update-branch-on-pr.yml

@@ -13,6 +13,7 @@ jobs:
       if: ${{ github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name && github.event.label.name == 'please test' }}
       with:
         ref: ${{ github.event.pull_request.head.sha }}
+        persist-credentials: true
         token: ${{ secrets.PAT_HLSML_BUILD_SPHINX }}
     - name: Push changes
       if: ${{ github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name && github.event.label.name == 'please test' }}