CLDC-2774 Update lettings materials (#1939)

* feat: update lettings materials

* feat: update tests

* refactor: lint

spec/helpers/collection_resources_helper_spec.rb

@@ -7,7 +7,7 @@ RSpec.describe CollectionResourcesHelper do
   describe "when displaying file metadata" do
     context "with pages" do
       it "returns correct metadata" do
-        expect(file_type_size_and_pages("2023_24_lettings_paper_form.pdf", number_of_pages: 8)).to eq("PDF, 286 KB, 8 pages")
+        expect(file_type_size_and_pages("2023_24_lettings_paper_form.pdf", number_of_pages: 8)).to eq("PDF, 285 KB, 8 pages")
       end
     end