Upgrade Postgres and start passing CancellationToken to PrepareAsync() if issue is resolved

[madelson]

See npgsql/npgsql#4209

[M4urici0GM]

Isnt this closed with postgre;'s #4559 ?

[madelson]

@M4urici0GM seems like it is, so this issue can be addressed in the next release of the postgres DistributedLock lib.

[Bartleby2718]

@madelson Given the latest comment, I think we'll need a major version bump for npgsql.

The breaking changes introduced in npgsql major version 6 don't seem to affect this library, but will this affect consumers?

[madelson]

@Bartleby2718 I agree; I think we'd go all the way to 8.x.