Do not use Django 'required' for radio selects

As this requires them to be True, whereas we just need to require that an option be entered.

RIGS/templates/partials/yes_no_radio.html

@@ -7,4 +7,4 @@
             <label class="custom-control-label" for="{{ radio.id_for_label }}">{{ radio.choice_label }}</label>
         </div>
     {% endfor %}
-</div> 
+</div>