change release trigger to push of new tag

.github/workflows/build.yml

@@ -1,10 +1,6 @@
 name: Build
 
-on:
-  pull_request:
-  release:
-    types:
-      - published
+on: [push, pull_request]
 
 jobs:
   build_wheels:
@@ -44,7 +40,7 @@ jobs:
   upload_pypi:
     needs: [build_wheels, build_sdist]
     runs-on: ubuntu-latest
-    if: github.event_name == 'release' && github.event.action == 'published'
+    if: github.event_name == "push" && startsWith(github.ref, "refs/tags")
     steps:
       - uses: actions/download-artifact@v2
         with: