Update dependency gitlab-styles to v7

This MR contains the following updates:

Package	Update	Change
gitlab-styles	major	~> 6.6.0 -> ~> 7.0.0

MR created with the help of gitlab-org/frontend/renovate-gitlab-bot

---

Configuration

📅 Schedule: "before 3am on Monday" (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.