Cache checking if books are on shelve in shelve button snippet

bookwyrm/templates/snippets/shelve_button/shelve_button_options.html

@@ -45,7 +45,13 @@
         <form name="shelve-{{ uuid }}-{{ shelf.identifier }}" action="/shelve/" method="post">
             {% csrf_token %}
             <input type="hidden" name="book" value="{{ active_shelf.book.id }}">
-            <button class="button {{ class }}" name="shelf" type="submit" value="{{ shelf.identifier }}" {% if shelf in book.shelf_set.all %} disabled {% endif %}>
+            <button
+                class="button {{ class }}"
+                name="shelf"
+                type="submit"
+                value="{{ shelf.identifier }}"
+                {% if book|is_book_on_shelf:shelf %} disabled {% endif %}
+            >
                 <span>{{ shelf.name }}</span>
             </button>
         </form>