Remove fixed term tenancy validation for periodic

app/models/lettings_log.rb

@@ -345,6 +345,11 @@ class LettingsLog < Log
     tenancy == 4
   end
 
+  def is_periodic_tenancy?
+    # 8: Periodic
+    tenancy == 8
+  end
+
   def is_internal_transfer?
     # 1: Internal Transfer
     referral == 1

app/models/validations/tenancy_validations.rb

@@ -24,7 +24,7 @@ module Validations::TenancyValidations
     ]
     rent_type_independent_conditions = [
       {
-        condition: !(record.is_secure_tenancy? || record.is_assured_shorthold_tenancy?) && is_present,
+        condition: !(record.is_secure_tenancy? || record.is_assured_shorthold_tenancy? || record.is_periodic_tenancy?) && is_present,
         error: I18n.t("validations.tenancy.length.fixed_term_not_required"),
       },
     ]