Update python-package.yml

Author: GoodManWEN

.github/workflows/python-package.yml

@@ -6,12 +6,12 @@ name: Build
 on:
   push:
     branches:
-      - 'master'
+      - 'main'
       - '[0-9].[0-9]+'  # matches to backport branches, e.g. 3.6
       - dev
   pull_request:
     branches:
-      - 'master'
+      - 'main'
       - '[0-9].[0-9]+'
   schedule:
     - cron:  '0 9 1 * *'  # Runs at 09:00 UTC on the 1st of every month