Switch to using GH App for pushing to gh-pages branch

Signed-off-by: bakhtin <[email protected]>

.github/workflows/release.yaml

@@ -13,6 +13,7 @@ jobs:
         uses: actions/checkout@v3
         with:
           fetch-depth: 0
+          persist-credentials: false
 
       - name: Configure Git
         run: |
@@ -28,9 +29,16 @@ jobs:
         run: |
           helm repo add bitnami https://charts.bitnami.com/bitnami
 
+      - name: Retrieve GH app token
+        id: generate-github-app-token
+        uses: getsentry/action-github-app-token@v2
+        with:
+          app_id: ${{ secrets.CHART_UPDATER_APP_ID }}
+          private_key: ${{ secrets.CHART_UPDATER_APP_KEY }}
+
       - name: Run chart-releaser
         uses: helm/[email protected]
         env:
-          CR_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+          CR_TOKEN: ${{ steps.generate-github-app-token.outputs.token }}
         with:
           charts_dir: charts