ci: add osx-arm64 to build workflow

Author: jsm174

.github/workflows/build.yml

@@ -19,6 +19,8 @@ jobs:
             rid: win-x86
           - os: macos-latest
             rid: osx-x64
+          - os: macos-latest
+            rid: osx-arm64
           - os: ubuntu-latest
             rid: linux-x64
     steps: