Update dependency bleach to v4

This MR contains the following updates:

Package	Type	Update	Change
bleach	ironbank-pypi	major	3.3.1 -> 4.0.0

⚠ Release Notes retrieval for this MR were skipped because no github.com credentials were available. If you are using the hosted GitLab app, please follow this guide. If you are self-hosted, please see this instruction instead.

---

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.