Code style improvements in JavaScript (#13159)

* JS-linter: fix trailing comma's

* Configure eslinter to ignore this onchange error.

app/javascript/mastodon/selectors/index.js

@@ -117,7 +117,7 @@ export const makeGetStatus = () => {
         map.set('account', accountBase);
         map.set('filtered', filtered);
       });
-    }
+    },
   );
 };