Disable audio help button when not available instead of hiding

<rikaitan.link>YzNjNTNmZWU1ODJjN2JhM2E5YzZkY2E0YjEyMzNkYTI4NjBjZTQxYgo=</rikaitan.link>

Author: jason-ojisan

ext/js/pages/settings/audio-controller.js

@@ -471,10 +471,10 @@ class AudioSourceEntry {
                 break;
         }
 
-        /** @type {?HTMLElement} */
+        /** @type {?HTMLButtonElement} */
         const helpNode = menu.bodyNode.querySelector('.popup-menu-item[data-menu-action=help]');
         if (helpNode !== null) {
-            helpNode.hidden = !hasHelp;
+            helpNode.disabled = !hasHelp;
         }
     }