Update code standards

[TavoNiievez]

No description provided.

[Naktibalda]

This code is odd, I think its only purpose was to get CI working, because it runs composer install in two separate directories.

[TavoNiievez]

Yes, it seems that it is, and it is still necessary... if I remove it I get:
PHP Fatal error: Uncaught Error: Class 'Symfony\Component\HttpKernel\Kernel' not found in /home/runner/work/module-symfony/module-symfony/framework-tests/src/Kernel.php:12
So I opted to encapsulate it in a separate method improving its documentation:

    /**
     * Ensures autoloader loading of additional directories.
     * It is only required for CI jobs to run correctly.
     */
    private function requireAdditionalAutoloader(): void
    {
        $autoLoader = codecept_root_dir() . 'vendor' . DIRECTORY_SEPARATOR . 'autoload.php';
        if (file_exists($autoLoader)) {
            require_once $autoLoader;
        }
    }