node-api: fix shutdown crashes

Refs: https://github.com/nodejs/node-addon-api/issues/906



Ensure that finalization is not defered during shutdown.
The env for the addon is deleted immediately after
iterating the list of finalizers to be run. Defering
causes crashes as the finalization uses the already
deleted env.

Signed-off-by: Michael Dawson <mdawson@devrus.com>

PR-URL: https://github.com/nodejs/node/pull/38492


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Gabriel Schulhof <gabrielschulhof@gmail.com>