Remove hardcoded batch size from find_in_batches in PatientStatusUpdater

While working on needs-consent sub-statuses and running data-replication
performance tests, we found that large batches were slow to process, while
a smaller batch size of 1000 completed significantly faster.

Author: jhenderson

app/lib/patient_status_updater.rb

@@ -92,7 +92,7 @@ def update_registration_statuses!
       .joins(session: :team_location)
       .where(team_location: { academic_year: academic_years })
       .includes(:attendance_records, :patient, :session, :vaccination_records)
-      .find_in_batches(batch_size: 10_000) do |batch|
+      .find_in_batches do |batch|
         batch.each(&:assign_status)
 
         Patient::RegistrationStatus.import!(