Upgrade @metamask/polling-controller to version 15.0.0

A new major version of `@metamask/polling-controller`, 15.0.0, 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.

Start by checking the project's dependency manifests for @metamask/polling-controller and confirm whether this package is present. Upgrade it to version 15.0.0, then run the project's existing validation or test commands to verify the dependency change does not break the app.

Written by the indexing model from the issue text.