bring back the auto-assigner

Author: briandfoy

.github/workflows/new_pull_request.yml

@@ -18,3 +18,6 @@ jobs:
     - uses: actions/checkout@v3
     - run: |
         perl .github/bin/labeler ${{ github.event.number }} add
+    - uses: hkusu/review-assign-action@v1
+      with:
+        reviewers: ${{ var.REVIEWERS }}