Update conditional

Author: maxrjones

.github/workflows/releases.yml

@@ -64,7 +64,7 @@ jobs:
   upload_pypi:
     needs: [build_artifacts, test_dist_pypi]
     runs-on: ubuntu-latest
-    if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags/v')
+    if: github.event_name == 'release'
     environment:
       name: releases
       url: https://pypi.org/p/zarr