Jakarta Data repository discovery

Currently we say:

> Exceptionally, the annotation `jakarta.data.repository.Repository` must be treated as a discoverable annotation type, even though it is not explicitly annotated `@Discoverable`.

I'm thinking that this is not quite enough, since it makes an implicit assumption that the Jakarta Data repository is deployed in the persistence unit, but application programs might want some other modular architecture.

I'm thinking it would be good to add some additional language that the EE container treats every Jakarta Data repository which depends on the persistence unit as a discoverable type of that persistence unit.

Start by reviewing the current Jakarta Data repository discovery wording quoted in this issue and the linked pull request #1144. Done means the specification language explains that repositories depending on the persistence unit are treated as discoverable types without assuming they are deployed in the persistence unit.

Written by the indexing model from the issue text.