update workflow for new default branch

Author: jkeen

.github/workflows/ci.yml

@@ -2,9 +2,7 @@ name: CI
 on:
   pull_request: {}
   push:
-    branches:
-      - master
-      - main
+    branches: [main]
 
 concurrency:
   group: ci-${{ github.head_ref || github.ref }}
@@ -27,7 +25,7 @@ jobs:
   publish:
     name: Release
     runs-on: ubuntu-latest
-    if: github.ref == 'refs/heads/master'
+    if: github.ref == 'refs/heads/main'
     needs: [test]
     steps:
       - name: Dispatch Release