Auto CherryPick commits to previous branches

.github/workflows/auto_cherry_pick.yml

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+# CI stages to execute against all branches on PR merge
+name: auto_cherry_pick_commits
+
+on:
+  pull_request_target:
+    types:
+      - closed
+
+jobs:
+  branch-matrix:
+    if: github.event.pull_request.merged == true && contains(github.event.pull_request.labels.*.name, 'CherryPick')
+    name: Generate a branch matrix to apply cherrypicks
+    runs-on: ubuntu-latest
+    outputs:
+      branches: ${{ steps.set-matrix.outputs.branches }}
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+      - id: set-matrix
+        run: echo "::set-output name=branches::$(git branch -rl --sort=-authordate 'origin/6.*.z' --format='%(refname:lstrip=-1)' | head -n2 | jq -cnR '[inputs | select(length>0)]')"
+  auto_cherry_picking:
+    if: github.event.pull_request.merged == true && contains(github.event.pull_request.labels.*.name, 'CherryPick')
+    name: Auto Cherry picking
+    needs: branch-matrix
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        to_branch: ${{ fromJson(needs.branch-matrix.outputs.branches) }}
+    steps:
+      - name: Checkout Nailgun
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+        if: matrix.to_branch != github.base_ref
+      - name: Cherry pick into ${{ matrix.to_branch }}
+        uses: carloscastrojumo/[email protected]
+        with:
+          branch: ${{ matrix.to_branch }}
+          labels: |
+            Auto_Cherry_Picked
+        # skipping PRs remote target_branch from cherrypicking into itself
+        if: matrix.to_branch != github.base_ref

.github/workflows/required_labels.yml

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+# CI jobs to check specific labels present / absent
+name: required_labels
+
+on:
+  pull_request:
+    types: [opened, labeled, unlabeled, synchronize]
+
+jobs:
+  cherrypick_label:
+    name: Enforcing cherrypick labels
+    runs-on: ubuntu-latest
+    steps:
+      - uses: mheap/github-action-required-labels@v2
+        with:
+          mode: exactly
+          count: 1
+          labels: "CherryPick, No-CherryPick"