Since the SPI split, the 'Swarm' object isn't necessarily available.
To that end, it implements `ArtifactLookup` from the SPI. And is passed to `getImplicitDeployments`.
By default, the 2-arg version of `getImplicitDeployments` calls the 1-arg without the `ArtifactLookup` object.
But some of our concrete subclasses don't handle that delegation appropriately.
And ultimately the 2-arg version is no longer needed, sincey `ArtifactLookup.get()` is globally available for anything that needs it. No reason to pass it through as a parameter to the method.
Therefore, we should return to the original 1-arg version, and let anyone who needs it do an `ArtifactLookup.get()` directly.