Update dotnet.yml

Author: prozolic

.github/workflows/dotnet.yml

@@ -21,9 +21,10 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: |
+            6.0.x
             8.0.x
     - name: Restore dependencies
-      run: dotnet restore
+      run: dotnet restore Utf8StringSplitter.slnx
     - name: Build
       run: dotnet build --no-restore
     - name: Test