CLDC-3000 Display available from date in the error message (#2058)

* Display available from date in the error message

* update created at in tests

app/models/validations/setup_validations.rb

@@ -150,7 +150,7 @@ private
     elsif absorbing_owning_organisation_inactive?(record)
       record.errors.add :startdate, I18n.t("validations.setup.startdate.invalid_absorbing_organisations_start_date.same_organisation",
                                            owning_organisation: record.owning_organisation.name,
-                                           owning_organisation_available_from: record.owning_organisation.created_at.to_formatted_s(:govuk_date))
+                                           owning_organisation_available_from: record.owning_organisation.available_from.to_formatted_s(:govuk_date))
     end
   end
 

spec/models/validations/setup_validations_spec.rb

@@ -136,8 +136,8 @@ RSpec.describe Validations::SetupValidations do
         Timecop.return
       end
 
-      let(:absorbing_organisation) { create(:organisation, created_at: Time.zone.local(2023, 2, 1, 4, 5, 6), available_from: Time.zone.local(2023, 2, 1, 4, 5, 6), name: "Absorbing org") }
+      let(:absorbing_organisation) { create(:organisation, created_at: Time.zone.local(2023, 1, 30, 4, 5, 6), available_from: Time.zone.local(2023, 2, 1, 4, 5, 6), name: "Absorbing org") }
-      let(:absorbing_organisation_2) { create(:organisation, created_at: Time.zone.local(2023, 2, 1), available_from: Time.zone.local(2023, 2, 1), name: "Absorbing org 2") }
+      let(:absorbing_organisation_2) { create(:organisation, created_at: Time.zone.local(2023, 1, 30), available_from: Time.zone.local(2023, 2, 1), name: "Absorbing org 2") }
       let(:merged_organisation) { create(:organisation, name: "Merged org") }
       let(:merged_organisation_2) { create(:organisation, name: "Merged org 2") }