Remove support for request accessible format form pilot

Now that there are no longer any departments taking part, remove code 
while we rethink.

app/presenters/content_item/attachments.rb

@@ -1,15 +1,9 @@
 module ContentItem
   module Attachments
     def attachment_details(attachment_id)
-      found_attachment = content_item.dig("details", "attachments")&.find do |attachment|
+      content_item.dig("details", "attachments")&.find do |attachment|
         attachment["id"] == attachment_id
       end
-
-      return unless found_attachment
-
-      found_attachment["attachment_id"] = found_attachment.delete("id")
-      found_attachment["owning_document_content_id"] = content_item["content_id"]
-      found_attachment
     end
   end
 end

test/views/content_items/attachments.html.erb_test.rb

@@ -14,17 +14,9 @@ class ContentItemsAttachmentsTest < ActionView::TestCase
 
   test "can render attachments using their metadata" do
     @content_item = PublicationPresenter.new(
-      {
-        "content_id" => "doc_content_id",
-        "details" => {
-          "attachments" => [
-            { "id" => "attachment_id",
-              "title" => "Some title",
-              "url" => "some/url",
-              "alternative_format_contact_email" => "[email protected]" },
-          ],
-        },
-      },
+      { "details" => { "attachments" => [{ "id" => "attachment_id",
+                                           "title" => "Some title",
+                                           "url" => "some/url" }] } },
       "/publication",
       ApplicationController.new.view_context,
     )
@@ -38,7 +30,6 @@ class ContentItemsAttachmentsTest < ActionView::TestCase
 
     assert_includes rendered, "gem-c-attachment"
     assert_includes rendered, "Some title"
-    assert_includes rendered, "href=\"/contact/govuk/request-accessible-format?content_id=doc_content_id&amp;attachment_id=attachment_id"
   end
 
   test "it prioritises pre-rendered attachments" do