[FIX] website_mail_channel: adapt snippet option to new UI

closes odoo/odoo#39062

X-original-commit: f097f07f95b7fc4a6acc84d7df1e3501fa555ec7
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/website_mail_channel/views/snippets.xml

@@ -42,10 +42,9 @@
 
     <xpath expr="//div[@id='snippet_options']" position="inside">
         <div data-js='subscribe'
-            data-selector=".js_follow_alias"
-            data-drop-near="p, h1, h2, h3, blockquote, .card"
-           >
-            <li data-select_mailing_list="" data-no-preview="true"><a>Change Discussion List</a></li>
+             data-selector=".js_follow_alias"
+             data-drop-near="p, h1, h2, h3, blockquote, .card">
+            <we-button data-select_mailing_list="" data-no-preview="true">Change Discussion List</we-button>
         </div>
     </xpath>