Setup .NET 8 on CI

Author: atifaziz

.github/workflows/build.yml

@@ -63,10 +63,12 @@ jobs:
       with:
         global-json-file: global.json
 
-    - name: Setup .NET SDK 6.0
+    - name: Setup .NET SDK 6.0, 8.0
       uses: actions/setup-dotnet@v3
       with:
-        dotnet-version: 6.0.x
+        dotnet-version: |
+          6.0.x
+          8.0.x
 
     - name: .NET Information
       run: dotnet --info