Hide search icon on larger screens that have search bar

It can be well argued that this should have been removed for screen readers
also, but i only removed it because it was visually confusing directly below
the search bar and clicking on it meant losing what you'd typed in, and this
doesn't apply to how search bar and search link will appear in screen readers.

web/themes/custom/geofresco/src/templates/elements/menu--nav-bulma.html.twig

@@ -57,6 +57,9 @@
             ])
           %}
         {% endif %}
+        {% if item.url|render == '/search' %}
+          {% set item_classes = item_classes|merge(['is-hidden-tablet']) %}
+        {% endif %}
       {% endif %}
       {{ link(
         item.title,