Nested Modals background muting #6771
Description
Bug description: When opening nested modals, the background does not mute properly behind the most recently opened modal.
You can see this happening on the examples site: https://valor-software.com/ngx-bootstrap/components/modals?tab=examples
(Try "Open Parent Modal" then "Open Second Modal").
ngx-bootstrap: 19.0.2
Angular: 20.0.0
Bootstrap: 5.3.6
Build system: Angular CLI
What I would expect the muting/fading to look like this: https://www.codeproject.com/Articles/1110966/Nested-Modal-Dialogs-using-Bootstrap