v0.12.4

Ractor v0.12.4 is released!

In this release there are 2 primary changes

1. We're adding the ability to runtime inspect the message type of an untyped ActorCell which can be helpful for supervision flows
2. We're also adding helpers for interacting with a supervisor's children (retrieval of the children, stopping them, and draining them) without having to have the supervisor keep additional handles around

Both are in #277