Is your feature request related to a problem? Please describe.

As discussed in https://lists.apache.org/thread/16bj5kngf2kfhqv3noxwfm7h9wlzvhyv

Cf. #2605

Describe the solution you'd like

EclipseLink persistence code and docs are to be removed.

Describe alternatives you've considered

No response

Additional context

No response