Use more standard function for primary key field find()

[Japoivvb]

https://github.com/Jonathancano2003/hospital-symfony-proyecto/blob/0efa9f1d1e8f95ccecf0d78726dd9084151a460d/src/Controller/NursesController.php#L45

https://symfony.com/doc/current/doctrine.html#fetching-objects-from-the-database