fix(list): address accessibility console error

[katie-bobbe-genesys]

Fix a console error that appears after opening a component that contains a gux-list then hovering over the first element:

gux-context-menu.html:1 Blocked aria-hidden on an element because its descendant retained focus. 
The focus must not be hidden from assistive technology users. Avoid using aria-hidden on a focused element or its ancestor. Consider using the inert attribute instead, which will also prevent focus. For more details, see the aria-hidden section of the WAI-ARIA specification at https://w3c.github.io/aria/#aria-hidden.
Element with focus: span
Ancestor with aria-hidden:  <span tabindex=​"-1" aria-hidden=​"true">​</span>​

I tried adding a test to catch this error but I could not get the accessibility test to fail.

[github-actions]

Demo will be published at https://apps.inindca.com/common-ui-docs/genesys-webcomponents/feature/COMUI-3499

[jordanstith15]

LGTM. Just needs the snapshots updated

[katie-bobbe-genesys]

There is an issue with having this focus target element. Both of the following cause accessibility issues

1. Having a focusable element with a role of aria-hidden is a violation
2. If you remove the aria-hidden, having an element with an invalid role as a descendent of the list is a violation.

I have removed this focus target span and instead put a tab index of -1 on the Host.

[katie-bobbe-genesys]

@daragh-king-genesys I am tagging you here because you seem to be the one who added this code. Can you remember if this code has any utility that I may be overlooking? I am removing it because it is causing unwanted focus behavior after my changes in the gux-list file.