[backport] Use new backport action (#126542)

.github/workflows/backport-next.yml

@@ -1,27 +0,0 @@
-on:
-  pull_request_target:
-    branches:
-      - main
-    types:
-      - labeled
-      - closed
-
-jobs:
-  backport:
-    name: Backport PR
-    runs-on: ubuntu-latest
-    if: |
-      github.event.pull_request.merged == true
-      && contains(github.event.pull_request.labels.*.name, 'auto-backport-next')
-      && (
-        (github.event.action == 'labeled' && github.event.label.name == 'auto-backport-next')
-        || (github.event.action == 'closed')
-      )
-    steps:
-      - name: Backport Action
-        uses: sqren/backport-github-action@v7.3.1
-        with:
-          github_token: ${{secrets.KIBANAMACHINE_TOKEN}}
-
-      - name: Backport log
-        run: cat /home/runner/.backport/backport.log

.github/workflows/backport.yml

@@ -9,6 +9,7 @@ on:
 jobs:
   backport:
     name: Backport PR
+    runs-on: ubuntu-latest
     if: |
       github.event.pull_request.merged == true
       && contains(github.event.pull_request.labels.*.name, 'auto-backport')
@@ -16,26 +17,11 @@ jobs:
         (github.event.action == 'labeled' && github.event.label.name == 'auto-backport')
         || (github.event.action == 'closed')
       )
-    runs-on: ubuntu-latest
     steps:
-      - name: Checkout Actions
-        uses: actions/checkout@v2
-        with:
-          repository: 'elastic/kibana-github-actions'
-          ref: main
-          path: ./actions
-
-      - name: Install Actions
-        run: npm install --production --prefix ./actions
-
-      - name: Fix Version Label Gaps
-        uses: ./actions/fix-version-gaps
+      - name: Backport Action
+        uses: sqren/backport-github-action@v7.4.0
         with:
           github_token: ${{secrets.KIBANAMACHINE_TOKEN}}
 
-      - name: Run Backport
-        uses: ./actions/backport
-        with:
-          github_token: ${{secrets.KIBANAMACHINE_TOKEN}}
-          commit_user: kibanamachine
-          commit_email: 42973632+kibanamachine@users.noreply.github.com
+      - name: Backport log
+        run: cat ~/.backport/backport.log