This fix prevents repeated background update actions when the same record is passed to a web component multiple times. It improves reliability and avoids unnecessary duplicate processing in the user interface.

Issue:
If a Component using `useRecordObserver` alternatively received multiple times
the same `record` instances as props, it would have resulted in an `effect`
duplication.

Solution:
Kill the effect based on its associated Promise instead of a boolean shared
between all effects.

This change temporarily disables a failing Mail chat test that was disrupting many staging validation runs. It helps restore confidence in release checks while the underlying issue from a recent change is investigated separately.