Super sidebar GlDisclosureDropdown update expanded styles selectors

What does this MR do and why?

Update super sidebar aria-expanded selectors to that toggle button elements get @include active-toggle; styles when GlDisclosureDropdown is open.

Screenshots or screen recordings

Before	After

How to set up and validate locally

• Enable the feature flag in rails console with rails c

Feature.enable(:super_sidebar_nav)

• Enable the "New navigation" setting toggle from the user dropdown

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.

Related to #395514 (closed)