Tool builds failing on net9.0 runs due to NU1102

[LoopedBard3]

We are hitting error NU1102: Unable to find package Microsoft.NETCore.App.Ref with version (= 8.0.11) (soon to fail to find reference (= 9.0.0) once #4523 is merged). This seems similar to dotnet/sdk#42379 where we have to add new feeds to make the latest packages available. This is affecting main branch performance-ci runs.

[LoopedBard3]

Found that this dependency was updated in this PR: dotnet/sdk#44257. We plan on taking the added feed <add key="darc-pub-dotnet-runtime-d398172" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/darc-pub-dotnet-runtime-d3981726/nuget/v3/index.json" /> and using it ourselves for now.

[DrewScoggins]

To solve this issue we have to options:

1. We can setup darc to automatically push the version and Nuget.config updates as they are created.
2. During release time we can just make sure that we update our Nuget.config manually when we move from stable version to stable version.