updating .NET version in workflow yml

Author: karissarjacobsen

.github/workflows/dotnet.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Setup .NET
       uses: actions/setup-dotnet@v2
       with:
-        dotnet-version: 6.0.x
+        dotnet-version: 8.0.x
     - name: setup-msbuild
       uses: microsoft/setup-msbuild@v1.1.3
     - name: Restore dependencies