Move from Hashicorp Vault to Openbao

Summary

Replacement of Vault by Openbao.

related references

RFE https://gitlab.com/sylva-projects/sylva/-/blob/ath/rfe-openbao/RFE/Use-OpenBao.md?ref_type=heads

Details

OpenBao is a fork of Hashicorp Vault. Switching from Vault to OpenBao is a matter of replacing the image reference, when OpenBao is officially released.