ci: move to main branch

.github/workflows/release.yml

@@ -3,7 +3,7 @@ name: release
 on:
   push:
     branches:
-      - master
+      - main
     paths-ignore:
       - '_docs/**'
       - '_examples/**'

.github/workflows/test.yml

@@ -3,14 +3,14 @@ name: test
 on:
   pull_request:
     branches:
-      - master
+      - main
     paths-ignore:
       - '_docs/**'
       - '_examples/**'
       - 'README*.md'
   push:
     branches:
-      - master
+      - main
     paths-ignore:
       - '_docs/**'
       - '_examples/**'