build(deps): bump autoprefixer from 10.4.20 to 10.4.21 (#521)

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 10.4.20 to 10.4.21.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/main/CHANGELOG.md)
- [Commits](postcss/autoprefixer@10.4.20...10.4.21)

---
updated-dependencies:
- dependency-name: autoprefixer
  dependency-type: direct:production
  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>

Author: dependabot[bot]

package-lock.json

@@ -30,7 +30,7 @@
     "@types/typescript": "^2.0.0",
     "@vercel/analytics": "^1.3.2",
     "asciidoctor": "^3.0.4",
-    "autoprefixer": "10.4.20",
+    "autoprefixer": "10.4.21",
     "badge-maker": "^4.1.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",