Fix setup of generator ref for pushes to main

Author: aj-foster

.github/workflows/generate.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Setup Ref (Push)
-        if: github.event_name == 'pull_request'
+        if: github.event_name == 'push'
         run: |
           echo "REF=main" >> $GITHUB_ENV