Update maven:3.8.4-openjdk-11 Docker digest to 906f82f

This MR contains the following updates:

Package	Type	Update	Change
maven	ironbank-docker	digest	49661b5 -> 906f82f

---

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 this update again.

---

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

---

This MR has been generated by Renovate Bot.