Bug: RouteCollection::resource() doesn't work with grouped rules

[rmilecki]

Describe the bug
When using routes group and ::resource() then methods receive method name as argument instead of segment. Example:

$routes->group('api', function($routes) {
	$routes->resource('news', ['controller' => 'Api\News' ]);
});

opening /api/news/show/123 results in CI4 calling ->show('show'); ('show' should be '123').

CodeIgniter 4 version
4.0.2

Affected module(s)
RouteCollection

Expected behavior, and steps to reproduce if appropriate
Things work as expected when using:

$routes->group('api', function($routes) {
	$routes->get('news/(:segment)',      'Api\News::show/$1');
});

and according to the documentation initial code using RouteCollection::resource() should be equivalent for that.

Context

• OS: Linux
• PHP version 7.4.2

[nyufeng]

uri is /api/news/123, not /api/news/show/123