Add workflow to sync upstream master daily

Automatically syncs Teradata/trino master with trinodb/trino master
on a daily schedule. Can also be triggered manually from GitHub UI.

Author: sc250072

.github/workflows/sync-upstream.yml

@@ -0,0 +1,16 @@
+name: Sync upstream master
+
+on:
+  schedule:
+    - cron: '0 6 * * *'  # Runs daily at 6 AM UTC
+  workflow_dispatch:       # Allow manual trigger from GitHub UI
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Sync fork with upstream
+        run: |
+          gh api repos/Teradata/trino/merge-upstream -f branch=master
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}