CI: Backport to release branches (#100067)

* update backport and release comms

* Backport to release branches and change docs source branch for publishing

* Add new workflows to CODEOWNERS

* Re-add removed line oops

* backport-testing -> grafana

* checkout grafana repo in backport action, reference repo / branch in reusable action

* generate -> create

.github/workflows/backport.yml

@@ -10,24 +10,19 @@ jobs:
     if: github.repository == 'grafana/grafana'
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout Actions
+      - name: Checkout
         uses: actions/checkout@v4
-        with:
-          repository: "grafana/grafana-github-actions"
-          path: ./actions
           ref: main
-      - name: Install Actions
-        run: npm install --production --prefix ./actions
       - name: "Generate token"
         id: generate_token
         uses: tibdex/github-app-token@b62528385c34dbc9f38e5f4225ac829252d1ea92
         with:
           app_id: ${{ secrets.GRAFANA_DELIVERY_BOT_APP_ID }}
           private_key: ${{ secrets.GRAFANA_DELIVERY_BOT_APP_PEM }}
+      - run: git config --global user.email '132647405+grafana-delivery-bot[bot]@users.noreply.github.com'
+      - run: git config --global user.name 'grafana-delivery-bot[bot]'
+      - run: git remote set-url origin "https://grafana-delivery-bot:${{ steps.generate_token.outputs.token }}@github.com/grafana/grafana.git"
       - name: Run backport
-        uses: ./actions/backport
+        uses: grafana/grafana-github-actions-go/backport@main
         with:
-          metricsWriteAPIKey: ${{secrets.GRAFANA_MISC_STATS_API_KEY}}
           token: ${{ steps.generate_token.outputs.token }}
-          labelsToAdd: "backport"
-          title: "[{{base}}] {{originalTitle}}"