Map branch name from sourcelink to RepositoryBranch for NuGet pack #13625
Description
NuGet Product(s) Involved
NuGet.exe, dotnet.exe
The Elevator Pitch
This is a companion issue for dotnet/sourcelink#1243.
Once sourcelink emits the source branch name, NuGet should map that value to RepositoryBranch (and follow the existing rules around allowing the user to override).
Additional Context and Details
No response