Using aggregate handlers for fetching an aggregate without return events or messages

[erdtsieck]

Is your feature request related to a problem? Please describe.
Sometime is just want to do something based on a message, but using information from my Marten aggregate. But the following code:

[AggregateHandler]
public static async Task HandleAsync(FooCommand command, Foo foo)
{
    // .. do stuff, but no events or messages to return
}

gives me the error:

No events are emitted from handler FooHandler handled by FooHandler.HandleAsync() even though it is marked as an action that would emit Marten events. Either return the events from the handler, or use the IEventStream service as an argument.

Describe the solution you'd like
No error, just execute

Describe alternatives you've considered
I now return an empty events or outgoingmessages array

Additional context
Discussed on Discord