Return a book

{
    "success": true,
    "message": "Book returned successfully!",
    "data": {
        "emprunt": {
            "_id": "JFNRSqCdmWmWkIp5czJix",
            "clientId": "Hp8Vzyzr3T3CZ3Om65eXF",
            "livreId": "PIWfXuZfLAJ8kuR-vJYs-",
            "dateRetourPrevu": "2026-01-05T21:31:53.596Z",
            "statut": "retourné",
            "dateEmprunt": "2025-02-19T04:43:52.534Z",
            "dateRetourEffectif": "2024-11-25T12:47:09.721Z"
        },
        "livre": {
            "_id": "KdhdFeYN9d7LQWSquOdzx",
            "isbn": "978-0-912253-51-0",
            "titre": "votum laudantium vulgus",
            "auteur": "Ms. Melody Gorczany",
            "editeur": "via cupressus rem",
            "langue": "Français",
            "description": "Odit uter candidus tui viscus repudiandae unde. Attero quisquam vix tergum theologus suffoco sustineo cavus cur. Canis super amoveo arca collum votum synagoga.",
            "quantite": 43,
            "anneePublication": 1925
        }
    }
}