When establishing a consistent collection for the timeseries upgrade check, we pass boost::none as the readTimestamp. This means we're not using the point-in-time read timestamp from the recovery unit, which can lead to inconsistent reads.

Other callers of establishConsistentCollection in the same file (e.g., line 178-182 and line 776-779) already correctly retrieve the PIT read timestamp from the recovery unit via getPointInTimeReadTimestamp().

The fix retrieves the PIT read timestamp and passes it to establishConsistentCollection.