Replace custom RandomVariable for WeibullBetaRV

[ricardoV94]

Reminder issue to remove the RandomVariable for WeibullBetaRV (introduced in #4640) once we have the automatic multiplication logp working (e.g., #4653)

[brandonwillard]

We might be able to use aesara.compile.builders.OpFromGraph in the interim. OpFromGraph will create a new Op to which we can assign a _logp specialization. This removes the need to create a RandomVariable Op for cases in which operations that are already covered by existing Ops are applied to existing RandomVariables.

[ricardoV94]

Same for the Wald which is just the numpy offering + optional shifting. #4711