Refactor backport workflow to use reusable-backport.yml

Updated backport workflow to use reusable workflow and added necessary secrets.

Author: linawolf

.github/workflows/backport.yml

@@ -1,22 +1,20 @@
 name: Backport
-
 on:
   pull_request_target:
-    types: [closed, labeled]
+    types:
+      - closed
+      - labeled
+
+permissions:
+  contents: write
+  pull-requests: write
 
 jobs:
   backport:
-    if: github.event.pull_request.merged == true
-    runs-on: ubuntu-latest
-
-    permissions:
-      contents: write
-      pull-requests: write
-
-    steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v 6.0.2
-
-      - name: Backport
-        uses: korthout/backport-action@4aaf0e03a94ff0a619c9a511b61aeb42adea5b02 # v4.2.0
-        with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
+    uses: TYPO3-Documentation/.github/.github/workflows/reusable-backport.yml@9d884304b1a5cdeeb2e21349a5bbfe52da5548d5
+    with:
+      label_pattern: "^backport (.+)$"
+    secrets:
+      APP_ID: ${{ secrets.APP_ID }}
+      APP_PRIVATE_KEY: ${{ secrets.APP_PRIVATE_KEY }}
+