Use latest .net

Author: micdah

.github/workflows/ci.yml

@@ -17,6 +17,8 @@ jobs:
       uses: actions/checkout@v2
       with:
         fetch-depth: 0
+    - name: Use .NET 6
+      uses: actions/setup-dotnet@v1
     - name: Build and Test
       run: ./Build.ps1
       shell: pwsh