Upgrade @metamask/sample-controllers to version 3.0.0

A new major version of `@metamask/sample-controllers`, 3.0.0, is now available. This issue has been assigned to you and your team because you code-own this package in the `core` repo. If this package is present in this project, please prioritize upgrading it soon to unblock new features and bugfixes.

Search the repository for @metamask/sample-controllers and inspect the package manifest where it is declared. First confirm whether this project uses the package; if it does, update it to version 3.0.0 and verify the project still builds and its relevant checks pass.

Written by the indexing model from the issue text.