Use Symfony MapUploadedFile attribute in CKEditor5ImageController::upload()

Problem/Motivation

In Symfony 7.1 a new attribute was added that lets you pass the UploadedFile as a controller param. See https://symfony.com/blog/new-in-symfony-7-1-mapuploadedfile-attribute

We can use this instead of the following code:

$upload = $request->files->get('upload');

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet