src: simplify AliasedBuffer lifetime management

Rely on the V8 garbage collector to take care of managing
the lifetime of the underlying memory of an `AliasedBuffer`.

PR-URL: https://github.com/nodejs/node/pull/26196


Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: James M Snell <jasnell@gmail.com>