Bump autoprefixer from 9.7.3 to 9.7.4 (#107)

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 9.7.3 to 9.7.4.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/master/CHANGELOG.md)
- [Commits](postcss/autoprefixer@9.7.3...9.7.4)

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

package.json

@@ -34,7 +34,7 @@
   },
   "dependencies": {},
   "devDependencies": {
-    "autoprefixer": "^9.7.3",
+    "autoprefixer": "^9.7.4",
     "chalk": "^3.0.0",
     "cheerio": "^1.0.0-rc.3",
     "cross-env": "^6.0.3",