Include all approved claims for the current AY

This slows down the report generation quite a bit, from 11s to 8
minutes, but it's a requirement from the Ops team. A job running once a
day for 8 minuts doesn' tseem too bad.

app/models/reports/duplicate_claims.rb

@@ -21,7 +21,6 @@ def initialize
       @claims = Claim
         .includes(:eligibility)
         .approved
-        .where.missing(:payments)
         .where(academic_year: AcademicYear.current)
         .select { |claim| Claim::MatchingAttributeFinder.new(claim).matching_claims.any? }
     end