build(deps): Bump postcss from 8.4.21 to 8.4.45 in /docs

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.21 to 8.4.45.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.21...8.4.45)

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

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

docs/package.json

@@ -26,7 +26,7 @@
     "@you54f/theme-github-codeblock": "^0.1.1",
     "autoprefixer": "^10.4.14",
     "clsx": "^1.2.1",
-    "postcss": "^8.4.21",
+    "postcss": "^8.4.45",
     "postcss-import": "^15.1.0",
     "prism-react-renderer": "^1.3.5",
     "react": "^17.0.2",