Build/Test Tools: Add the regenerator-runtime script as a dependency to wp-polyfill.
In [51146], the core-js package replaced the deprecated @babel//polyfill one. The core-js package builds wp-polyfill from a configuration provided by @wordpress/babel-preset-default instead of copying a one size fits all polyfill.
That change caused an issue where plugins and themes relying on the regenerator-runtime script being included in the wp-polyfill.js file encountering fatal JavaScript errors.
This adds the regenerator-runtime package to Core and registers it as a dependency for wp-polyfill. While Core does not require regenerator-runtime, it will allow for a smoother transition to using core-js.
This dependency will be removed in a future version of WordPress, so developers are encouraged to add regenerator-runtime as a dependency for any custom script that requires it.
Follow up to [51146].
Props gziolo, herregroen, jeherve, hellofromtonya, peterwilsoncc.
Fixes #52941.