Refactor sales_log_spec to use fixed date values for end date and date after end date, mimics change of year without changing year

spec/models/sales_log_spec.rb

@@ -1087,8 +1087,8 @@ RSpec.describe SalesLog, type: :model do
 
   context "when form year changes and LA is no longer active" do
     let!(:sales_log) { create(:sales_log) }
-    let(:end_date) { generate_different_date_within_collection_year(Time.zone.now, end_date_override: Time.zone.now + 14.days) }
-    let(:date_after_end_date) { generate_different_date_within_collection_year(end_date, start_date_override: Time.zone.now, end_date_override: Time.zone.now + 14.days) }
+    let(:end_date) { Time.zone.local(2025, 3, 30) }
+    let(:date_after_end_date) { Time.zone.local(2025, 3, 31) }
 
     before do
       LocalAuthority.find_by(code: "E08000003").update!(end_date:)