automation: Update docker-gitlab Docker tag to v18.2.4

This MR contains the following updates:

Package	Update	Change
docker-gitlab	patch	18.2.2-ce.0 -> 18.2.4-ce.0

---

Configuration

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