Removing a topic declaration did not cause errors for subscribers

[bradleydwyer]

@Export
@Topic(name = "prices", partitions = 1)
interface PriceTopic : WriteableTopic<Price, SinglePartitionMapper>

removing this left the topic available to the subscriber

//ftl:subscribe ticker.prices from=latest

and still visible in the console

module ticker {
  export topic prices ticker.Price  
    +partitions 1

[matt2e]

This would be due to kotlin modules not removing generated versions of deleted code. cc @stuartwdouglas.
These same steps work fine with go modules.

[matt2e]

We don't have a ticket for that issue though. Ill make one and mark this one a dupe of that

[matt2e]

Dupe of #4603