chore(deps-dev): bump @guardian/prettier from 7.0.0 to 8.0.0

Bumps [@guardian/prettier](https://github.com/guardian/csnx) from 7.0.0 to 8.0.0.
- [Release notes](https://github.com/guardian/csnx/releases)
- [Commits](https://github.com/guardian/csnx/compare/@guardian/prettier@7.0.0...@guardian/prettier@8.0.0)

---
updated-dependencies:
- dependency-name: "@guardian/prettier"
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -27,7 +27,7 @@
   },
   "devDependencies": {
     "@guardian/eslint-config-typescript": "^5.0.0",
-    "@guardian/prettier": "^7.0.0",
+    "@guardian/prettier": "^8.0.0",
     "@guardian/tsconfig": "^0.2.0",
     "@types/jest": "^27.4.1",
     "@types/js-yaml": "^4.0.9",