Display confirmation dialog before changing user timezone

Here's a reroll to use core/once which should be compatible with D10

Included the D10 compatibility patch by accident. Here's another attempt.

$(once('once-id', document, context)).length; unfortunately is 0.

Looks like $(once('once-id', document.body, context)).length; is 1. So updating patch.

Closing the jquery dialogs doesn't clear the body scroll locks, so I made some changes to call close() on Drupal.dialog.
Changed dialogClass to classes according to https://www.drupal.org/node/3440844 →

Removed the custom close function, as it interferes with the default close behavior, and doesn't remove the lock from the body tag, when closing the dialog by clicking on the close icon.