FIX: Convert jQuery array to JS array

FIX: Convert jQuery array to JS array

diff --git a/app/assets/javascripts/discourse/app/lib/link-mentions.js b/app/assets/javascripts/discourse/app/lib/link-mentions.js
index a0773cb..04f2e05 100644
--- a/app/assets/javascripts/discourse/app/lib/link-mentions.js
+++ b/app/assets/javascripts/discourse/app/lib/link-mentions.js
@@ -64,11 +64,13 @@ function updateFound($mentions, usernames) {
 export function linkSeenMentions($elem, siteSettings) {
   const $mentions = $("span.mention:not(.mention-tested)", $elem);
   if ($mentions.length) {
-    const usernames = $mentions.map((_, e) =>
-      $(e)
-        .text()
-        .substr(1)
-    );
+    const usernames = [
+      ...$mentions.map((_, e) =>
+        $(e)
+          .text()
+          .substr(1)
+      )
+    ];
     updateFound($mentions, usernames);
     return usernames
       .uniq()

GitHub sha: 720cd57f

This commit appears in #10566 which was merged by eviltrout.