Remove onclick as we no longer need

templates/form/form--user-login-form.html.twig

@@ -13,5 +13,5 @@
 <form{{ attributes }}>
   {{ children }}
 </form>
-<button id="adfs-login-link" class="button--primary"  onClick='ADFSButton_onClick()'>Log In Via ADFS</button>
+<button id="adfs-login-link" class="button--primary">Log In Via ADFS</button>
 <button id="local-login-link">Log In Locally</button>