Remove existing display of postage

It’s redundant now we’re displaying it as part of the template.

app/templates/views/notifications/notification.html

@@ -52,9 +52,6 @@
         </p>
       {% else %}
         {% if sent_with_test_key %}
-          <p>
-            Postage: {{ postage }} class
-          </p>
           {% if is_precompiled_letter %}
             <p>
               This letter passed our checks, but we will not print it because you used a test key.
@@ -68,9 +65,6 @@
           <p>
             {{ letter_print_day }}
           </p>
-          <p>
-            Postage: {{ postage }} class
-          </p>
           <p>
             Estimated delivery date: {{ estimated_letter_delivery_date|string|format_date_short }}
           </p>

app/templates/views/templates/_template.html

@@ -22,10 +22,6 @@
               </a>
             </div>
           {% endif %}
-            <div class="column-whole" id="postage">
-              <h2 class="heading-small heading-inline">Postage</h2>:
-              {{ template_postage or current_service.postage }} class
-            </div>
         {% else %}
           {% if current_user.has_permissions('send_messages', restrict_admin_usage=True) %}
             <div class="column-half">