Enable macos CI (#5)

Author: HTHou

.github/workflows/dotnet.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ ubuntu-latest, windows-latest ]
+        os: [ ubuntu-latest, windows-latest, macos-latest ]
 
     steps:
     - uses: actions/checkout@v4