tractor/nooz/257.feature.rst

Add trionics.maybe_open_context() an actor-scoped async multi-task context manager resource caching API.

Adds an SC-safe cacheing async context manager api that only enters on the first task entry and only exits on the last task exit while in between delivering the same cached value per input key. Keys can be either an explicit key named arg provided by the user or a hashable kwargs dict (will be converted to a list[tuple]) which is passed to the underlying manager function as input.