reltags: remove mark inactive button from artist urls.

In related tags, remove the (X) button next to artist urls for marking
them as inactive. This was broken because it didn't record the change
to the is_active flag in the artist history.

app/views/related_tags/_source_tags.html.erb

@@ -20,7 +20,6 @@
               <li>
                 <% if url.is_active %>
                   <%= external_link_to url.url, truncate: 64, strip: :scheme, target: "_blank" %>
-                  <%= link_to tag.i(class: "fas fa-minus-circle"), artist_url_path(id: url.id, artist_url: { is_active: false }), remote: true, method: :put, "data-confirm": "This will mark the URL as inactive. Continue?" %>
                 <% else %>
                   <del><%= external_link_to url.url, truncate: 64, strip: :scheme, target: "_blank" %></del>
                 <% end %>