Smallrye Reactive Messaging 4 on the main branch

[ozangunalp]

We are pleased to announce that Smallrye Reactive Messaging main branch development will continue on version 4.

The version 4 includes migrating from javax to jakarta namespace, including dependencies compatible with the jakarta namespace.

Since release 3.20.0, 4.x releases have been released in parallel, following the main branch with Jakarta migration.
The next release 4.3.0 will be performed from the main branch will also include the Mutiny 2.0 update with Flow API support.

2.x branch, which was inactive, is abandoned and will receive no further changes.
3.x branch will continue receiving certain updates and backported changes.