Bump Microsoft.SourceLink.GitHub
Bump Microsoft.SourceLink.GitHub

Bumps [Microsoft.SourceLink.GitHub](https://github.com/dotnet/sourcelink) from 1.0.0-beta2-18618-05 to 1.0.0-beta2-19270-01.
- [Release notes](https://github.com/dotnet/sourcelink/releases)
- [Commits](https://github.com/dotnet/sourcelink/commits/1.0.0-beta2-19270-01)
EamonNerbonne/ZlibWithDictionary