GuzzleHttp/Client not found

Ao executar php ./src/buscar-cursos.php, tenho este erro de retorno:

PS ~\devlopment\alura\php\buscador_cursos_alura> php .\src\buscar-cursos.php
PHP Fatal error:  Uncaught Error: Class "GuzzleHttp\Client" not found in ~\devlopment\alura\php\buscador_cursos_alura\src\buscar-cursos.php:7
Stack trace:
#0 {main}
  thrown in ~\devlopment\alura\php\buscador_cursos_alura\src\buscar-cursos.php on line 7

Fatal error: Uncaught Error: Class "GuzzleHttp\Client" not found in ~\devlopment\alura\php\buscador_cursos_alura\src\buscar-cursos.php:7
Stack trace:
#0 {main}
  thrown in ~\devlopment\alura\php\buscador_cursos_alura\src\buscar-cursos.php on line 7

Composer.json

{
    "name": "teste/buscador-cursos",
    "description": "Projeto que buscas os cursos no site da Alura",
    "type": "library",
    "autoload": {
        "psr-4": {
            "Teste\\BuscadorCursos\\": "src/"
        }
    },
    "require": {
        "guzzlehttp/guzzle": "^7.4",
        "symfony/dom-crawler": "^6.1",
        "symfony/css-selector": "^6.1"
    }
}

Já executei: composer update composer dump && composer update

O que pode ser?

Versões:

PHP 8.1.8 (cli) (built: Jul  5 2022 23:10:34) (NTS Visual C++ 2019 x64)
Copyright (c) The PHP Group
Zend Engine v4.1.8, Copyright (c) Zend Technologies

Composer version 2.3.10 2022-07-13 15:48:23