Later in the stack, we need to return SendMessagePayload (which has +interface: CallSingleKeyserverEndpointResultInfoInterface) as a result of DM Ops. which is encrypting and queueing messages on Tunnelbroker, not keyserver call.
Alternatives:
- Use tunnelbroker instead of none - I think this is even worse for readability because the type is associated with Keyserver.
- Remove interface from SendMessagePayload - this seems the best and I think it's safe because I wasn't able to find any usage of interface.
I am not familiar with why we need this at all, so curious about the reviewers' perspective.
Depends on D13319