Fix deprecation warning when using symfony/http-foundation:8.1

[W0rma]

This PR fixes the following deprecations warnings when using this library with Symfony 8.1:

Since symfony/http-foundation 8.1: Directly setting property "request" of "Symfony\Component\HttpFoundation\Request" is deprecated; pass the POST data as a constructor argument or call "initialize()" instead.
Since symfony/http-foundation 8.1: Directly setting property "files" of "Mock_Request_8e3a88e1" is deprecated; pass files as a constructor argument or call "initialize()" instead.
Since symfony/http-foundation 8.1: Directly setting property "query" of "Mock_Request_8e3a88e1" is deprecated; pass
Since symfony/http-foundation 8.1: Directly setting property "request" of "Mock_Request_8e3a88e1" is deprecated; pass the POST data as a constructor argument or call "initialize()" instead.

From https://github.com/symfony/symfony/blob/8.1/UPGRADE-8.1.md#httpfoundation:

Deprecate setting public properties of Request and Response objects directly; use setters or constructor arguments instead

[W0rma]

The error in https://github.com/FriendsOfSymfony/FOSRestBundle/actions/runs/29490571636/job/87595412270?pr=2436 regarding scrutinizer seems to be unrelated:

--2026-07-16 10:22:48-- https://scrutinizer-ci.com/ocular.phar
Resolving scrutinizer-ci.com (scrutinizer-ci.com)... 104.26.1.85, 172.67.75.7, 104.26.0.85
Connecting to scrutinizer-ci.com (scrutinizer-ci.com)|104.26.1.85|:443... connected.
HTTP request sent, awaiting response... 403 Forbidden
2026-07-16 10:22:48 ERROR 403: Forbidden.