Update dependency keycloak/keycloak to v21

This MR contains the following updates:

Package	Update	Change
keycloak/keycloak	major	20.0.2 -> 21.0.1

---

Release Notes

keycloak/keycloak

v21.0.1

Compare Source

v21.0.0

Compare Source

v20.0.5

Compare Source

v20.0.3

Compare Source

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

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

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

---

• If you want to rebase/retry this MR, check this box