Automatically label PRs to sync by default

Signed-off-by: Matty Widdop <18513864+MattyTheHacker@users.noreply.github.com>

Author: MattyTheHacker

.github/workflows/pr-auto-label.yml

@@ -0,0 +1,16 @@
+name: "Automatically mark PRs to sync"
+
+on:
+  pull_request:
+
+jobs:
+  labeler:
+    permissions:
+      pull-requests: write
+
+    runs-on: ubuntu-latest
+    steps:
+      - run: gh pr edit $PR --add-label sync
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          PR: ${{ github.event.number }}