OSS CI for stacked commits (#24)

Summary:
Pull Request resolved: #24

Make CI run for ghstacked commits, maybe?
ghstack-source-id: 285475797

Reviewed By: colin2328

Differential Revision: D75176799

fbshipit-source-id: 242462e52581d5f31cc74f54ceca07139ebed5b9

Author: zdevito

.github/workflows/test.yml

@@ -7,6 +7,7 @@ on:
   pull_request:
     branches:
       - main
+      - gh/**
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref == 'refs/heads/main' && github.run_number || github.ref }}