Spring HibernateJpaVendorAdapter refers to org.hibernate.dialect.Oracle12cDialect that does not exist in recent Hibernate versions

As a follow-up of #31889, another dialect is impacted with the same problem.

Comment From: snicoll

It's similar to the mysql arrangement, the dialect with the "default name" got deprecated and then undeprecated, see https://github.com/hibernate/hibernate-orm/commit/9565d499af2d4efd71eeaad1101982a8183c3884