Changing the AWS profile doesn't update the S3 buckets.

## Problem
I have multiple AWS accounts connected. When I switch from one to another, it doesn't get reflected in the listed AWS accesses. I need to restart the extension to make it work.
## Steps to reproduce the issue

1. Go to 'Connected with profile'
2. Change the profile
3. List the s3 buckets

## Expected behavior
I expect to see the available S3 buckets for the selected profile. However, the list doesn't get updated. Once I close and reopen it, the list updates.
## System details (run `AWS: About` and/or `Amazon Q: About`)

- OS: Sequoia 15.7.3
- Visual Studio Code version: 1.105.1
- AWS Toolkit version: 4.0.0
- Amazon Q version:

Reproduce the issue in the AWS Toolkit for VS Code by switching profiles from “Connected with profile” and listing S3 buckets. Trace the profile-change and bucket-list refresh flow; done means the available buckets update for the selected profile without restarting the extension.

Written by the indexing model from the issue text.