Update staircase page test with 2025

spec/models/form/sales/pages/staircase_spec.rb

@@ -7,6 +7,9 @@ RSpec.describe Form::Sales::Pages::Staircase, type: :model do
   let(:page_definition) { nil }
   let(:subsection) { instance_double(Form::Subsection, form: instance_double(Form, start_date: Time.zone.local(2023, 4, 1))) }
 
+  context "when start year is 2024" do
+    let(:subsection) { instance_double(Form::Subsection, form: instance_double(Form, start_date: Time.zone.local(2023, 4, 1)), id: "sale_information") }
+
     before do
       allow(subsection.form).to receive(:start_year_2025_or_later?).and_return(false)
     end
@@ -26,4 +29,18 @@ RSpec.describe Form::Sales::Pages::Staircase, type: :model do
     it "has the correct description" do
       expect(page.description).to be_nil
     end
+  end
+
+  context "when start year is >= 2025" do
+    let(:subsection) { instance_double(Form::Subsection, form: instance_double(Form, start_date: Time.zone.local(2023, 4, 1)), id: "setup") }
+
+    before do
+      allow(subsection.form).to receive(:start_year_2025_or_later?).and_return(true)
+    end
+
+    it "has correct subsection" do
+      expect(page.subsection).to eq(subsection)
+    end
+  end
+
 end