Bump postcss from 8.5.1 to 8.5.18

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.1 to 8.5.18.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.1...8.5.18)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.18
  dependency-type: direct:development
...

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

Author: dependabot[bot]

packages/web/package.json

@@ -96,7 +96,7 @@
     "autoprefixer": "10.4.20",
     "eslint-config-next": "15.1.6",
     "identity-obj-proxy": "3.0.0",
-    "postcss": "8.5.1",
+    "postcss": "8.5.18",
     "react-docgen-typescript-loader": "3.7.2",
     "react-test-renderer": "18.3.1",
     "tailwindcss": "3.4.17"