Fix incorrect markup around phase banner

app/views/layouts/application.html.erb

@@ -47,14 +47,12 @@
       end
     %>
 
-    <aside class="govuk-width-container">
+    <div class="govuk-width-container">
       <%= render GovukComponent::PhaseBannerComponent.new(
         tag: { text: 'Beta' },
         text: "This is a new service – #{govuk_mail_to("test@mhclg.gov.uk", "give feedback or report a problem", subject: "Feedback about Lettings and Sales of Social Housing in England Data Collection")}".html_safe
       ) %>
-    </aside>
 
-    <div class="govuk-width-container">
       <div role="navigation">
         <%= content_for(:before_content) %>
       </div>