NuGet.config of MakeConst sample can be deleted

[Youssef1313]

It existed there before the testing library was published to NuGet.org. I believe it can be safely deleted now.

https://github.com/dotnet/docs/blob/main/docs/csharp/roslyn-sdk/tutorials/snippets/how-to-write-csharp-analyzer-code-fix/NuGet.config

Parallel PR should be made in dotnet/samples

This also requires updating the testing package version. The version should match the updated template, see dotnet/roslyn-sdk#855.

[Youssef1313]

@gewarren IIRC, there was some security warning for the NuGet.config that you suppressed or something like that. It can be re-enabled once this is fixed.

[BillWagner]

Thanks for noting this @Youssef1313

Do you want to submit a PR for this? If so, I'll assign it to you.

Otherwise, I'll take care of it later this week.

[Youssef1313]

Thanks for pinging @BillWagner. Opening a PR now.