Updated .NET version to 8.0

Author: datvm

.github/workflows/build-github-pages.yml

@@ -15,7 +15,7 @@ jobs:
     - name: Setup .NET SDK
       uses: actions/setup-dotnet@v3.2.0
       with:
-        dotnet-version: 7.x
+        dotnet-version: 8.x
     - name: Install .NET WASM Build Tools
       run: dotnet workload install wasm-tools
     - name: Publish .NET project