Source root not calculated correctly in AzDo with ArtifactsPath set to Build.ArtifactStagingDirectory

In an AzDo pipeline, I have a project with `UseArtifactOutput` set to true and in the build step, it passes `-p:ArtifactsPath=$(Build.ArtifactStagingDirectory)` to put them in the AzDo arifacts staging dir. The side effect is that some generated files, like the `.Version.cs` are not properly scrubbed with the right roots and are thus not reproducible.

With the `ArtifactsPath` being outside the source dir:

Without overridding the `ArtifactsPath`, the artifacts dir is under the source dir, so is scrubbed correctly.

Tested with .NET 10 SDK RC2