Upgrade to JavaEE/JakartaEE 8

[erikgb]

Problem description

Java EE has become Jakarta EE, and we have to migrate to Jakarta EE to be able to upgrade our "EE" dependencies like servlet, jsp and jaxb.

Jakarta EE 8 is the first release of Jakarta EE, and is fully compatible with Java EE 8 - which means that we can migrate dependencies to jakarta artifacts before addressing the massive code migration of javax to jakarta. I am assuming #3559 is addressing the latter and will only be resolved by an upgrade to Jakarta EE 9. Jakarta EE also releases a BOM, which will make it significantly easier to manage Jakarta EE dependencies.

Preferred solution

I have worked on a draft PR for a long time already (#4397), and I suggest creating a new PR with the changes proposed in the WIP PR.

One of the main issues seems to be that our Solr/ES compatibility tests pull in dependencies to a legacy version of Jetty that blocks us from using a newer version of Jetty (compatible with JavaEE 8) in this module.

Are you interested in contributing a solution yourself?

Yes

Alternatives you've considered

No response

Anything else?

No response