fix: github action to keep auto merge prs in sync with develop (#1567)

Co-authored-by: jekabskarklins <jekabs.karklins@ess.eu>

Author: jekabs-karklins

.github/workflows/sync-auto-merge-prs.yml

@@ -0,0 +1,41 @@
+name: Sync auto-merge PRs with develop
+
+on:
+  schedule:
+    - cron: '0 0-5 * * *'
+  workflow_dispatch:
+
+jobs:
+  sync-one-pr:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Find and sync one behind auto-merge PR
+        env:
+          GH_TOKEN: ${{ secrets.PR_SYNC_PAT }}
+        run: |
+          PR_LIST=$(gh pr list \
+            --repo "$GITHUB_REPOSITORY" \
+            --base develop \
+            --state open \
+            --json number,title,autoMergeRequest,mergeStateStatus)
+
+          BEHIND=$(echo "$PR_LIST" | jq '[.[] | select(
+            .autoMergeRequest != null and
+            .mergeStateStatus == "BEHIND"
+          )]')
+
+          COUNT=$(echo "$BEHIND" | jq 'length')
+          echo "Found $COUNT auto-merge PR(s) behind develop"
+
+          if [ "$COUNT" -eq 0 ]; then
+            echo "Nothing to sync."
+            exit 0
+          fi
+
+          INDEX=$((RANDOM % COUNT))
+          PR_NUMBER=$(echo "$BEHIND" | jq --argjson i "$INDEX" '.[$i].number')
+          PR_TITLE=$(echo "$BEHIND"  | jq -r --argjson i "$INDEX" '.[$i].title')
+
+          echo "Selected PR #$PR_NUMBER: $PR_TITLE"
+          gh pr update-branch "$PR_NUMBER" --repo "$GITHUB_REPOSITORY"
+          echo "Branch updated."