[Sync EN] Add user and password to PDO_MYSQL DSN (#5706)

[github-actions]

Commit: https://github.com/php/doc-en/commit/57a2f4c34cc3c74a7040282dcd60b906738a523d
PR: https://github.com/php/doc-en/pull/5706

Zu aktualisierende DE-Dateien

• reference/pdo_mysql/reference.xml