Assess the impact of ConfigureAwait(false) on updates to data-bound notification entities

[ajcvickers]

See #8898 (comment)

Triage: I'll take a look to see if it could make sense to do ConfigureAwait(true) for this path, like we did for SaveChanges. Otherwise we could consider some sort of per-query or context option to just do true everywhere, if we think that's important.

Also, look into EnableCollectionSynchronization can be recommended and where it works.