feat: auto pick non-breaking changes

.github/pull_request_template.md

@@ -12,3 +12,8 @@ Please conduct a thorough self-review before opening the PR.
 ## Summary
 
 *Please include a succinct description of the purpose and content of the PR. What problem does it solve, and how? Link issues, discussions, other PRs, and anything else that will help the reviewer.*
+
+
+#### Non-Breaking changes
+
+If this PR includes non-breaking changes, select the `non-breaking` label. On merge, CI will automatically cherry-pick the commit to a PR against the release branch.

.github/workflows/ci-cherry-pick.yml

@@ -0,0 +1,68 @@
+name: Cherry-Pick to Release Branch
+
+on:
+  pull_request:
+    branches:
+      - main
+    types:
+      - closed
+
+run-name: Cherry pick `${{ github.event.pull_request.title }}` to release branch
+
+jobs:
+  cherry-pick:
+    if: ${{ (github.event.pull_request.merged == true) && (contains(github.event.pull_request.labels.*.name, 'non-breaking')) }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout branch
+        uses: actions/checkout@v3
+        with:
+          ref: main
+
+      - name: Configure Git
+        run: |
+          git config --global user.name 'GitHub Action'
+          git config --global user.email 'action@github.com'
+
+      - name: Cherry-pick commit
+        run: |
+          set -x
+          git fetch --all
+          COMMIT_SHA=$(git rev-parse HEAD)
+          echo "COMMIT_SHA=$COMMIT_SHA" >> $GITHUB_ENV
+
+          RELEASE_BRANCH="release/$(git branch -r | grep 'origin/release/[0-9]\+\.[0-9]' | sed 's/.*release\///' | sort -V | tail -n1)"
+          echo "RELEASE_BRANCH=$RELEASE_BRANCH" >> $GITHUB_ENV
+
+          BRANCH=pick/non-breaking-$(date +%s)
+          echo "BRANCH=$BRANCH" >> $GITHUB_ENV
+
+          git checkout $RELEASE_BRANCH
+          git checkout -b $BRANCH
+          git cherry-pick -x $COMMIT_SHA
+
+      - name: Push to Remote
+        run: |
+          git push origin ${{ env.BRANCH }}
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v3
+        with:
+          token: ${{ secrets.CF_BACKEND_GITHUB_TOKEN }}
+          commit-message: Cherry-picked from ${{ env.COMMIT_SHA }}
+          title: "Cherry-Pick ${{ env.COMMIT_SHA }} to ${{ env.RELEASE_BRANCH }}"
+          branch: ${{ env.BRANCH }}
+          base: '${{ env.RELEASE_BRANCH }}'
+          reviewers: 'martin-chainflip'
+          labels: cherry-pick
+
+      - name: Notify on failed cherry-pick
+        if: failure() || cancelled()
+        env:
+          DISCORD_USERNAME: "Release Picker"
+          DISCORD_WEBHOOK: ${{ secrets.CF_DISCORD_ALERTS_CRITICAL }}
+        uses: Ilshidur/action-discord@0.3.2
+        with:
+          args: |
+            🍒⚠️ Sorry **${{ github.actor }}**, The attempt to cherry-pick `${{ env.COMMIT_SHA }}` on to `${{ env.RELEASE_BRANCH }}` was unsuccessful
+            Please check the [GitHub job](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}) to see what went wrong.