ngbAccordionToggle is not disabled when ngbAccordionItem is disabled

[Daniel Rose]

Bug description:

When an ngbAccordionItem is disabled, the button should also be disabled. However, this is done inconsistently.

• If the button is a ngbAccordionButton, it is disabled.
• If the button is a ngbAccordionToggle, it is not disabled. Instead, this must be done explicitly. This is a breaking change from the component-based accordion.

In the example, you can see that <button ngbAccordionToggle [disabled]="second.disabled"> is needed to set the button into its disabled state, which is not needed for the <button ngbAccordionButton>.

If you compare it to "Custom Header" in the old release (https://ng-bootstrap.github.io/releases/13.x/#/components/accordion/examples), no explicit code is needed (<button ngbPanelToggle>)

Link to minimally-working StackBlitz that reproduces the issue:

https://stackblitz.com/edit/angular-sda4bv?file=src%2Fapp%2Faccordion-basic.html

Versions of Angular, ng-bootstrap and Bootstrap:

Angular: 17.0.9

ng-bootstrap: 16.0.0

Bootstrap: 5.3.2