n-api: do not require JS Context for `napi_async_destroy()`

Allow the function to be called during GC, which is a common use case.

Fixes: https://github.com/nodejs/node/issues/27218

PR-URL: https://github.com/nodejs/node/pull/27255


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>