Update autoprefixer requirement from 9.4.0 to 9.4.2

Updates the requirements on [autoprefixer](https://github.com/postcss/autoprefixer) to permit the latest version.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/master/CHANGELOG.md)
- [Commits](https://github.com/postcss/autoprefixer/commits/9.4.2)

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

package.json

@@ -27,7 +27,7 @@
   ],
   "license": "MIT",
   "dependencies": {
-    "autoprefixer": "9.4.0",
+    "autoprefixer": "9.4.2",
     "minimatch": "^3.0.2",
     "postcss": "7.0.6"
   },