Accessibility issue with pagination disabled buttons

[tsaputo]

Bug description:

Disabled buttons are focusable with TAB.

Versions of ngx-bootstrap, Angular, and Bootstrap:

ngx-bootstrap: ^9.0.0

Angular: 14.1.1

Bootstrap: ^5.2.0

Build system: Angular CLI, System.js, webpack, starter seed:

Expected behavior

If the button is disabled - it is not focusable with tab .

Actual behaviour

https://user-images.githubusercontent.com/9536093/188916605-dc92e40c-68d1-4042-acee-d398510e8a8e.mov