Proper native dependency management is planned, but not completed (you can see design docs on GitHub). The new syntax only supports project and pre-built libraries at the moment (no remote dependencies).
What used to happen, under the covers, was the dependency was converted into two dependencies:
Then resolved into temporary directories and wired into the options for the compiler/linker. It’s possible to do that yourself still. You’d have to create your own configuration, download task, generate pre-built library blocks for each dependency, etc. If you don’t have to worry about too many variants, you can probably cut some corners (native dependency management is hard).