Our dotnet integration tests copy a working .NET SDK folder, then patch the NuGet assemblies, and use this copy/patched .NET SDK to run tests.

We're upgrading to a version of newtonsoft.json higher than what the .NET SDK currently has (we're both upgrading at the same time), but until our CI pipeline start using builds of .NET SDK with a high enough version, we need to copy it ourselves.

Here's what needs to be removed:
https://github.com/NuGet/NuGet.Client/pull/4167/files/0e2f6a70900839b1f8670f8fd471d36bf1974df0#diff-8a81e906729d9dc1d11f635564b6eed54b859ab8aaacb3713fc29b19189f0f3b