Update build.yaml

Author: mayneyao

.github/workflows/build.yaml

@@ -1,10 +1,8 @@
-# This workflows will upload a Python Package using Twine when a release is created
-# For more information see: https://help.github.com/en/actions/language-and-framework-guides/using-python-with-github-actions#publishing-to-package-registries
-
 name: build
 
 on:
   push:
+    branches:
     - master
 
 jobs: