Remove H2 dependency from Hibernate ORM 6 module

https://issues.redhat.com/browse/WFLY-14474 added the H2 database jdbc driver to the Hibernate ORM module to avoid the "unable to determine H2 database version" warning. That should be resolved by Hibernate ORM 6 changes to get the H2 database version from the DatabaseMetaData during the second persistence unit phase bootstrap.

So we can now remove the h2 module dependency from the Hibernate module.