Bump Microsoft.SourceLink.GitHub from 1.1.1 to 8.0.0

Bumps [Microsoft.SourceLink.GitHub](https://github.com/dotnet/sourcelink) from 1.1.1 to 8.0.0.
- [Release notes](https://github.com/dotnet/sourcelink/releases)
- [Commits](https://github.com/dotnet/sourcelink/commits)

---
updated-dependencies:
- dependency-name: Microsoft.SourceLink.GitHub
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Directory.Build.props

@@ -20,6 +20,6 @@
   <ItemGroup>
     <PackageReference
      Condition="!$(MSBuildProjectName.EndsWith('Tests'))"
-     Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All"/>
+     Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All"/>
   </ItemGroup>
 </Project>