Upgrade to Hibernate 6

[sdelamo]

Issue description

https://hibernate.org/orm/releases/6.1/

[dstepanov]

The best way would be to create a hibernate6 module because not everyone is going to update to Hibernate 6 that fast. Also, Hibernate 6 doesn't support reactive compared to Hibernate 5.

[sdelamo]

@dstepanov @radovanradic Can we close this?