Pubsec page updates

1. Change Summary

• Content updates for PubSec page (content doc: https://docs.google.com/document/d/1tfOWuzqnsob2gcM8c9fXR_Ov1ReK81VtdGq6dYv60I4/edit?tab=t.0)

2. QA Checklist

[This merge request should follow all best practices utilizing our team code standards and our project's development documentation]

[Provide concise steps to test the changes]

Review App

Production	Review app	Screenshot
https://about.gitlab.com/solutions/public-sector/	https://1569-pubsec-content.about.gitlab-review.app/solutions/public-sector/	Screenshot

3. Deployment Steps

[List key deployment steps or configurations]

Closes #1569 (closed)