domain: avoid circular memory references

Avoid circular references that the JS engine cannot see through
because it involves an `async id` ⇒ `domain` link.

Using weak references is not a great solution, because it increases
the domain module’s dependency on internals and the added calls into
C++ may affect performance, but it seems like the least bad one.

Backport-PR-URL: https://github.com/nodejs/node/pull/27749
PR-URL: https://github.com/nodejs/node/pull/25993
Fixes: https://github.com/nodejs/node/issues/23862


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Vladimir de Turckheim <vlad2t@hotmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Refael Ackermann <refack@gmail.com>