build(deps-dev): bump the npm group across 1 directory with 2 updates

Bumps the npm group with 2 updates in the /website directory: [autoprefixer](https://github.com/postcss/autoprefixer) and [postcss](https://github.com/postcss/postcss).


Updates `autoprefixer` from 10.4.18 to 10.4.20
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/main/CHANGELOG.md)
- [Commits](postcss/autoprefixer@10.4.18...10.4.20)

Updates `postcss` from 8.4.35 to 8.4.47
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.35...8.4.47)

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

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

website/package.json

@@ -4,8 +4,8 @@
         "build": "echo $BASE_URL; hugo --minify --baseURL=${BASE_URL}"
     },
     "devDependencies": {
-    "autoprefixer": "^10.4.18",
-    "postcss": "^8.4.35",
+    "autoprefixer": "^10.4.20",
+    "postcss": "^8.4.47",
     "postcss-cli": "^11.0.0"
   }
 }