It is not uncommon for `sql.active_record` subscribers to rely on
thread local or fiber local state. For instance the `buffered-logger`
gem buffer the logs in a thread variable.

With the introduction of async queries, the `sql.active_record`
events can now be produced from a background thread and that break
some expectations.

This makes it hard for subscriber to map the event to the request
or job that scheduled it.

That is why I believe we should instead store the event and
publish it back on the calling thread when the results are
accessed.