Update dependency @types/mocha to v9

This MR contains the following updates:

Package	Type	Update	Change
@types/mocha	devDependencies	major	^8.2.0 -> ^9.0.0

---

Configuration

📅 Schedule: "every weekend" (UTC).

🚦 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.

---

This MR has been generated by Renovate Bot.