Removing a resource provider with consumers breaks resource publishing.

Currently, the agent publishes all resources considered "used" via the resource provider manager whenever it is asked to publish a subportion. If a resource provider with active users (e.g., tasks or even just executors) was removed, but a user stays around this will fail any resource publishing on that node since a "used" resource provider is not subscribed.

We should either update the agent code to just deltas, or provide a workaround of the same effect in the resource provider manager.