Add/Allow adding readiness probes to EventBus

[Nizar-opt]

Is your feature request related to a problem? Please describe.
We noticed that EventBus's StatefulSet doesn't have readiness probes, although it has startup & liveness probes.

Describe the solution you'd like
Add (or Allow adding) readiness probes to EventBus StatefulSet

Describe alternatives you've considered
No alternatives. Adding this would let PDBs know when pods are actually healthy.

Additional context
Add any other context or screenshots about the feature request here.

---

Message from the maintainers:

If you wish to see this enhancement implemented please add a 👍 reaction to this issue! We often sort issues this way to know what to prioritize.