VerticalManifest.xml is not getting bundled in artifacts tarball

[MichaelSimons]

When you enable poisoning, the VerticalManifest.xml is not getting bundled in artifacts tarball. This is caused by an msbuild target ordering issue and an property dependency.

1. CreatePrivateSourceBuiltArtifactsArchive depends on the AssetManifestFilePath property to copy the VerticalManifest.xml - https://github.com/dotnet/dotnet/blob/5b423a447e09f11fc68720a5f78bb7c1d610b11e/eng/PublishSourceBuild.props#L129-L130
2. AssetManifestFilePath is defined inside of PublishToAzureDevOpsArtifacts which is not a DependsOnTargets for CreatePrivateSourceBuiltArtifactsArchive - https://github.com/dotnet/dotnet/blob/5b423a447e09f11fc68720a5f78bb7c1d610b11e/src/arcade/src/Microsoft.DotNet.Arcade.Sdk/tools/Publish.proj#L283-L284
3. In "normal" builds, PublishToAzureDevOpsArtifacts runs before CreatePrivateSourceBuiltArtifactsArchive so everything works. When poisoning is enabled, the order is swapped therefore the logic to copy the VerticalManifest.xml no-ops because AssetManifestFilePath is empty.

While this is not an issue in production today, I am concerned this could break because of the missing dependency declaration.