Remove sourcelink entries from Version.Details.xml

[ViktorHofer]

testfx/eng/Version.Details.xml

Lines 58 to 66 in b110758

	<Dependency Name="Microsoft.SourceLink.GitHub" Version="1.1.0-beta-21228-01">
	<Uri>https://github.com/dotnet/sourcelink</Uri>
	<Sha>4b584dbc392bb1aad49c2eb1ab84d8b489b6dccc</Sha>
	<SourceBuild RepoName="sourcelink" ManagedOnly="true" />
	</Dependency>
	<Dependency Name="Microsoft.SourceLink.AzureRepos.Git" Version="1.1.0-beta-21228-01">
	<Uri>https://github.com/dotnet/sourcelink</Uri>
	<Sha>4b584dbc392bb1aad49c2eb1ab84d8b489b6dccc</Sha>
	</Dependency>

Sourcelink packages aren't transitively brought in via Arcade anymore as sourcelink is now part of the .NET SDK. These entries shouldn't be required anymore and can be deleted.