build(deps-dev): bump postcss from 8.5.14 to 8.5.15

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.14 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@8.5.14...8.5.15)

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

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

Author: dependabot[bot]

package.json

@@ -43,7 +43,7 @@
     "expect": "^30.2.0",
     "jest": "^30.2.0",
     "jest-environment-jsdom": "^30.2.0",
-    "postcss": "8.5.14",
+    "postcss": "8.5.15",
     "prettier": "^3.5.3",
     "prettier-plugin-tailwindcss": "^0.7.1",
     "tailwindcss": "3.4.19",