Bump postcss from 8.4.41 to 8.4.45 in /doc (#3153)

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.41 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@8.4.41...8.4.45)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

doc/package.json

@@ -1,7 +1,7 @@
 {
   "devDependencies": {
     "autoprefixer": "^10.4.0",
-    "postcss": "^8.3.7",
+    "postcss": "^8.4.45",
     "postcss-cli": "^11.0.0"
   }
 }