Use render_map to render the map component

This is done for consistency. We always use `render_map`, but forgot to
do the same in commit 529357c98.

app/components/admin/geozones/index_component.html.erb

@@ -34,5 +34,5 @@
   <h3><%= t("admin.geozones.index.geojson_map") %></h3>
   <p class="help-text"><%= t("admin.geozones.index.geojson_map_help") %></p>
 
-  <%= render Shared::MapLocationComponent.new(nil, geozones_data: geozones_data) %>
+  <%= render_map(nil, geozones_data: geozones_data) %>
 </section>

app/components/admin/geozones/index_component.rb

@@ -1,6 +1,7 @@
 class Admin::Geozones::IndexComponent < ApplicationComponent
   include Header
   attr_reader :geozones
+  use_helpers :render_map
 
   def initialize(geozones)
     @geozones = geozones