ci: add release condition

Author: jamieweavis

.github/workflows/build.yml

@@ -30,6 +30,7 @@ jobs:
   release:
     needs: [build]
     runs-on: ubuntu-latest
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4