Update dependency postcss to v8.4.39

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
postcss (source)	8.4.38 -> 8.4.39

---

Release Notes

postcss/postcss (postcss)

### [`v8.4.39`](https://togithub.com/postcss/postcss/blob/HEAD/CHANGELOG.md#8439) [Compare Source](https://togithub.com/postcss/postcss/compare/8.4.38...8.4.39) - Fixed `CssSyntaxError` types (by [@​romainmenke](https://togithub.com/romainmenke)).

---

Configuration

📅 Schedule: Branch creation - "every weekend" in timezone Europe/Stockholm, Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box

---

This PR has been generated by Mend Renovate. View repository job log here.