fix: fix header link to point to gov start page

src/Dfe.ContentSupport.Web/Views/Shared/_CsHeader.cshtml

@@ -10,7 +10,7 @@
             </div>
         </div>
         <div class="dfe-width-container dfe-header__service-name">
-            <a href="/self-assessment" class="dfe-header__link--service">Plan technology for your school</a>
+            <a href="/" class="dfe-header__link--service">Plan technology for your school</a>
         </div>
     </div>
     <partial name="_Hero" model="@Model.Heading"/>