Update dependency quay.io/keycloak/keycloak to v19

This MR contains the following updates:

Package	Type	Update	Change
quay.io/keycloak/keycloak	ironbank-docker	major	18.0.2-legacy -> 19.0.0-legacy
quay.io/keycloak/keycloak		major	18.0.2-legacy -> 19.0.0-legacy
quay.io/keycloak/keycloak	stage	major	18.0.2-legacy -> 19.0.0-legacy

---

Configuration

📅 Schedule: At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this MR and you won't be reminded about these updates again.

---

• If you want to rebase/retry this MR, click this checkbox.

---

This MR has been generated by Renovate Bot.