Changes to workflow files (#2204)

Co-authored-by: Rögl-Brunner Michel <Michel.Roegl-brunner@htl-braunau.int>

.github/workflows/auto-update-app-headers.yml

@@ -17,6 +17,13 @@ jobs:
       pull-requests: write
 
     steps:
+      - name: Generate a token
+        id: generate-token
+        uses: actions/create-github-app-token@v1
+        with:
+          app-id: ${{ vars.APP_ID }}
+          private-key: ${{ secrets.APP_PRIVATE_KEY }}
+
       # Step 1: Checkout repository
       - name: Checkout repository
         uses: actions/checkout@v2
@@ -71,7 +78,7 @@ jobs:
                        --base main \
                        --label "automated pr"
         env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_TOKEN: ${{ steps.generate-token.outputs.token }}
       
       - name: Approve pull request
         if: env.changed == 'true'