Update ci.yml

Author: mtrezza

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Set up .NET
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 6.0
+          dotnet-version: '6.0'
       - name: Install dependencies
         run: dotnet restore
       - name: Run linting