We need to make the same change as #3908 to the official build yaml file:

https://github.com/dotnet/machinelearning/blob/master/build/vsts-ci.yml

"phases" in AzDO yaml files are the old schema. We should be using "jobs", which is the "new" schema.

See https://github.com/dotnet/arcade/blob/master/Documentation/AzureDevOps/PhaseToJobSchemaChange.md for more info.