Fixes#10296. When an async `useEffect` runs twice or more before
resolving, we use the Abort Controller API to cancel previous events.
This works by instantiating a new ref on each run, and if a previous ref
was detected, it will be aborted and a new instance will be set up for
the next run. However, while the logic was aborting previous instances
as expected, it was failing to instantiate a new one.
abb51b98eb