Spinner element should be jquery element

Problem/Motivation

I'm using D10.4 with ui_suite_bootstrap and layout_pragraph.

I configure Mercury Editor Edit Tray theme for ui_suite_bootstrap theme on admin/config/content/mercury-editor.

When i edit a node and submit changes, spinner displays but doesn't hide anymore.

Console log display error :

Uncaught TypeError: this.progress.element.parent is not a function
    /themes/contrib/ui_suite_bootstrap/assets/js/misc/ajax.js?sr9w4y:114

First thought was about a ui_suite_bootstrap issue since i don't have it with gin and claro, except looking at /mercury_editor/source/js/ajax-progress.js, i see this.progress.element is an html element, not a jQuery element as expected by ui_suite_bootstrap.

Digging in core, i see this.progress.element is instanciate as jquery element, and every where in code use this element as a jQuery object.

I agree we should use more vanillaJs and less jQuery, but we should align with how the core instanciate this element.

Proposed resolution

Use jQuery to override the element.