PHPCS is installed via Composer and we use the Composer autoloader for loading all these classes.

To avoid conflicts with any other plugins bundling PHPCS, we should prefix the dependencies' classes with something like PHP-Scoper. See https://github.com/googleforcreators/web-stories-wp/ and https://github.com/google/site-kit-wp for some prior art where this is done.