Cannot create tarball off of 6.0.1 release tag

[MichaelSimons]

The reason for this is 6.0.1 was an MSRC release therefore the release was based on commits that originated from within the Microsoft internal repos. These commits were merged to the public repos as part of the release but the installer's Version.Details.xml, which source-build utilizes to create the tarball, references the internal commits.

The correct thing to do long term is to ensure the urls are in a valid form so anyone can utilize these urls from release tags. This is something that is going to take time to solve. In the meantime the tarball creation logic should handle translating the internal repos to the public repos.

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.