Move to .NET 8 SDK

Author: rainersigwald

.github/workflows/dotnet.yml

@@ -14,12 +14,12 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Setup .NET
-      uses: actions/setup-dotnet@v1
+      uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 5.0.x
+        dotnet-version: 8.0.x
     - name: Restore dependencies
       run: dotnet restore
     - name: Build
-      run: dotnet build --no-restore
+      run: dotnet build --no-restore -tl
     - name: Test
       run: dotnet test --no-build --verbosity normal