Automatically sync commits from upstream

Change-type: patch
Signed-off-by: Kyle Harding <kyle@balena.io>

.github/workflows/upstream-sync.yml

@@ -0,0 +1,54 @@
+name: "Upstream Sync"
+
+on:
+  schedule:
+    # at 07:00 every Monday and Thursday
+    - cron: "0 7 * * 1,4"
+  pull_request:
+    branches:
+      - master
+      - main
+  workflow_dispatch:
+
+jobs:
+  sync_branch:
+    runs-on: ubuntu-latest
+    name: Sync branch
+
+    strategy:
+      matrix:
+        branch:
+          - dunfell
+          - honister
+          - kirkstone
+          - thud
+          - warrior
+          - pyro
+          - rocko
+          - sumo
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ matrix.branch }}
+
+      # https://github.com/aormsby/Fork-Sync-With-Upstream-action
+      - name: Sync upstream commits
+        id: sync
+        uses: aormsby/Fork-Sync-With-Upstream-action@v3.4
+        with:
+          target_sync_branch: ${{ matrix.branch }}
+          target_repo_token: ${{ secrets.GITHUB_TOKEN }}
+          upstream_sync_branch: ${{ matrix.branch }}
+          host_domain: git.yoctoproject.org
+          upstream_sync_repo: git/poky
+          test_mode: ${{ github.event_name == 'pull_request' }}
+
+      - name: New commits synced
+        if: steps.sync.outputs.has_new_commits == 'true'
+        run: echo "New commits were synced." >> $GITHUB_STEP_SUMMARY
+
+      - name: No new commits
+        if: steps.sync.outputs.has_new_commits == 'false'
+        run: echo "There were no new commits." >> $GITHUB_STEP_SUMMARY