feat: support dynamic HTTP response status code via request attribute

[Griffon-Weglot]

Q	A
Branch?	main
Tickets	Closes #7903
License	MIT
Doc PR	api-platform/docs#...

Allow processors to dynamically override the HTTP response status code by setting the _api_response_status request attribute.

Use case: A single POST endpoint that returns 200 when the operation is processed synchronously, and 202 when it is dispatched asynchronously.

  // In a processor                                                                                                                                                                                                                         
  $request = $context['request'] ?? null;                                                                                                                                                                                                     
  $request?->attributes->set('_api_response_status', 200);                                                                                                                                                                                  

The change is fully backward-compatible: when the attribute is not set, the existing behavior is unchanged.