user_profile: Invalidate user group state after closing the user modal.

A regression was introduced in #33075 where user groups are only
rendered on the user profile modal once per page load since
user_groups_list_widget was not getting cleaned upon closing the modal.

web/src/user_profile.ts

@@ -510,6 +510,7 @@ export function hide_user_profile(): void {
 
 function on_user_profile_hide(): void {
     user_streams_list_widget = undefined;
+    user_groups_list_widget = undefined;
     user_profile_subscribe_widget = undefined;
     const base = get_current_hash_category();
     // After closing the user profile, if the hash consists of `#user`