Fix race in `scheduled_actor`
Fix race in `scheduled_actor`

The race caused a heap use after free.

actor-framework/actor-framework,DavadDi/actor-framework,nq-ebaratte/actor-framework,DavadDi/actor-framework,nq-ebaratte/actor-framework,nq-ebaratte/actor-framework,actor-framework/actor-framework,actor-framework/actor-framework,actor-framework/actor-framework,DavadDi/actor-framework,DavadDi/actor-framework,nq-ebaratte/actor-framework