Update unittests.yml

Author: awcullen

.github/workflows/unittests.yml

@@ -17,10 +17,10 @@ jobs:
       uses: actions/setup-dotnet@v1
       with:
         dotnet-version: '3.1.x'
-    - name: Setup dotnet 5.0
+    - name: Setup dotnet 6.0
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: '5.0.x'
+        dotnet-version: '6.0.x'
     - name: Build with dotnet
       run: dotnet build --configuration Release
     - name: Run unit tests