CU - Remove references to ChevronUp and ChevronDown in documentation

[juancstlm-a6]

Proposed Change

With #9721 being merged and the removal of ChevronUp.svg and ChevronDown.svg the docs should be updated to remove references to those files as it is causing Github Action failures when building the Documentation. See here https://github.com/department-of-veterans-affairs/va-mobile-app/actions/runs/11131052124/job/30931752925?pr=9736

Why Should We Prioritize?

Fix failing github actions to prevent normalization of deviance.

Coding Time Estimation

1

Testing Considerations

Checking if the [Documentation] Test Build Github action succeeds should be sufficient testing

Checklist

• Add the relevant team label (Health, global, design system, API, Qa and Release etc.)
• Attach to ticket to the relevant Team Tech Debt Epic epic (old frontend engineering epic is no longer in use as each team is managing their code's technical debt and code upkeep work)