Update push-to-myget.yml

.github/workflows/push-to-myget.yml

@@ -10,7 +10,7 @@ jobs:
       - name: Setup .NET Core SDK
         uses: actions/setup-dotnet@master
         with:
-          dotnet-version: '6.0.x'
+          dotnet-version: '7.0.x'
           include-prerelease: true
         
       - name: setup nuget.exe