CLDC-4215: Don't run validate_discounted_ownership_value if mortgageused is 3

I don't think this should have ever been turned on. if we don't know the mortgage we can't assume info in this check

app/models/validations/sales/sale_information_validations.rb

@@ -77,7 +77,7 @@ module Validations::Sales::SaleInformationValidations
   def validate_discounted_ownership_value(record)
     return unless record.saledate && record.form.start_year_2024_or_later?
     return unless record.value && record.deposit && record.ownershipsch
-    return unless record.mortgage || record.mortgageused == 2 || record.mortgageused == 3
+    return unless record.mortgage || record.mortgageused == 2
     return unless record.discount || record.grant || record.type == 29
 
     tolerance = record.value_with_discount_tolerance