PackageSpecWriter should write out original string for versions instead of allocating a new one

[jeffkl]

NuGet Product Used

MSBuild.exe, dotnet.exe

Product Version

All

Worked before?

No response

Impact

None

Repro Steps & Context

The SetCentralDependencies method writes out the PackageVersion items to the project.assets.json and uses the normalized version. This section is only read by our reader which parses it again during read so there's no need to allocate another string and instead should just write out the original string.

https://github.com/NuGet/NuGet.Client/blob/dev/src/NuGet.Core/NuGet.ProjectModel/PackageSpecWriter.cs#L668

Originally reported internally: https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1828422

Verbose Logs

No response

[jeffkl]

Fixed in NuGet/NuGet.Client#5619