ci(sync-patches): guard conflict-resolution path against empty commits (#3124)

When all stable->main conflicts are in release-managed files (package.json
versions, etc.) and auto-resolution keeps main's version for every one,
the index becomes clean. The unguarded git commit then exits 1 and the
workflow run shows red despite stable and main being correctly in sync.

Mirror the existing 'no changes to sync' guard from the no-conflict path.

Author: caio-pizzol

.github/workflows/sync-patches.yml

@@ -93,6 +93,13 @@ jobs:
 
             # Check if all conflicts are resolved
             if [ -z "$(git diff --name-only --diff-filter=U)" ]; then
+              # If every conflict was auto-resolved to main's version, the index
+              # may now be clean (nothing to sync). Same guard as the no-conflict path.
+              if git diff --cached --quiet; then
+                echo "No changes to sync - auto-resolution kept main's version for everything."
+                exit 0
+              fi
+
               git commit -m "chore: merge stable into main (release conflicts auto-resolved)"
               git push origin "$SYNC_BRANCH"