Cannot Unsubscribe Amazon Q Developer Pro

## Problem
1. Go to '...'
2. Click on 'Manage Q Developer Developer Pro Subscription'
3. See error
":To increase your limit, subscribe to a Kiro subscription. Choose the right [plan](https://kiro.dev/pricing/) and log in to [app.kiro.dev](https://app.kiro.dev/signin), pick the plan, and once active, you should be able to continue and use Q and Kiro services with the new limits. If you have questions, refer to our [FAQs](https://aws.amazon.com/q/developer/faqs/?p=qdev&z=subnav&loc=8#general)"

If I open app.kiro.dev and login with builder account

Screen show :
Error
Failed to load usage data: Authentication required or access denied.

## Steps to reproduce the issue

## Expected behavior
Open the subscription panel to unsubs user from amazon developer Pro.

## System details (run `AWS: About` and/or `Amazon Q: About`)

- OS:
- Visual Studio Code version:
- AWS Toolkit version:
- Amazon Q version:

Start by reproducing the failure from the Amazon Q Developer Pro subscription management panel and compare it with the authentication error shown at app.kiro.dev. Collect the missing OS, VS Code, AWS Toolkit, and Amazon Q versions, then trace the subscription panel's request and verify that a valid builder account can open the unsubscribe flow successfully.

Written by the indexing model from the issue text.