Update to version 6.0.201of .NET SDK on build server

Author: TysonMN

.github/workflows/master.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 5.0.403
+        dotnet-version: 6.0.201
     - name: Install dependencies
       run: dotnet restore
     - name: Build