Only show district dropdown if there is more than one district in the database

app/views/layouts/_header.html.erb

@@ -9,13 +9,13 @@
       </div>
 
       <div class="col d-flex justify-content-end">
-        <select id="select-district" class="form-select" name="district">
-          <% @districts.each do |district| %>
-            <option class="district-options" value="<%= district_url_for(district: district, academic_year: @academic_year) %>" <%= @district.slug == district.slug ? "selected" : nil %>>
-            <%= district.name %>
-            </option>
-          <% end %>
-        </select>
+        <select id="select-district" class="form-select" name="district" <%= District.count == 1 ? "hidden": ""  %> >
+            <% @districts.each do |district| %>
+              <option class="district-options" value="<%= district_url_for(district: district, academic_year: @academic_year) %>" <%= @district.slug == district.slug ? "selected" : nil %>>
+              <%= district.name %>
+              </option>
+            <% end %>
+          </select>
 
         <select id="select-school" class="ms-3 form-select" name="school">
           <% @schools.each do |school| %>