v6: UI Shell - Header item hangs the browser tab

[eduardmarcinco]

Steps to reproduce:
Run Storybook from the next branch.
Open UI Shell group, browser tab hangs.

I also updated real application to v6 that is using UI Shell and observed the same behavior.

I digged into it a bit and this new getter might be the culprit here triggering unbounded CD loop.
https://github.com/carbon-design-system/carbon-components-angular/blame/next/src/ui-shell/header/header-item.component.ts#L79C8-L88