Should we remove the timeout from ActorProxy by default

## Describe the proposal

ActorProxy uses a default `HttpClient` which comes with a 100 second timeout. This might be surprising, because users can add their own cancellation policies, but can't be more permissive than what the built-in timeout supports.

We're adding other mechanisms to give users control over this, but I wanted to raise the topic specifically - should we remove the default timeout? Have you been impacted by this?