Deleting nuget.config. Syncs with .NET 8 RTM (#237)

## Purpose
We're removing nuget.config in the local /app folder so we rely on the
factory state laid down by the .NET SDK and what is in the users'
cascading nuget config [User global
nuget.config](https://learn.microsoft.com/en-us/nuget/consume-packages/configuring-nuget-behavior#config-file-locations-and-uses)

Signed-off-by: Paul Yuknewicz <[email protected]>
Co-authored-by: Paul Yuknewicz <[email protected]>

Author: paulyuk