test: use raw strings (#164)

Author: VisualBean

Diff for: .github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
     - name: Setup .NET
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: '6.0.x'
+        dotnet-version: '8.0.x'
         include-prerelease: true
     - name: Restore dependencies
       run: dotnet restore