Add the PR #484 towncrier fragment for removing
`ActorNursery.run_in_actor()`, `Portal.wait_for_result()` and
`Portal.result()`.
Point callers to `to_actor.run()`, `Portal.run()` or
`Portal.open_context()` according to task ownership and dialog shape.
Review: PR #484 (OpenCode)
https://github.com/goodboy/tractor/pull/484#pullrequestreview-5025383596
(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))