Switch specs to use new nav

What does this MR do and why?

As part of #420121 (closed) this MR switches some features specs to run with the new "super sidebar" navigation, instead of the old one.

Screenshots or screen recordings

No changes, only specs.

How to set up and validate locally

Check CI logs and/or run some of the changed specs locally with WEBDRIVER_HEADLESS=0 to see that they really do use the new nav.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.