deps(deps-dev): bump postcss in /marketing in the npm-minor-patch group

Bumps the npm-minor-patch group in /marketing with 1 update: [postcss](https://github.com/postcss/postcss).


Updates `postcss` from 8.5.12 to 8.5.15
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.12...8.5.15)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.15
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: npm-minor-patch
...

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

Author: dependabot[bot]

marketing/package-lock.json

@@ -21,7 +21,7 @@
     "@tailwindcss/typography": "^0.5.12",
     "autoprefixer": "^10.5.0",
     "concurrently": "^9.0.0",
-    "postcss": "^8.5.12",
+    "postcss": "^8.5.15",
     "postcss-cli": "^11.0.0",
     "tailwindcss": "^3.4.19"
   },