fix: upgrade autoprefixer from 10.4.20 to 10.4.21

Snyk has created this PR to upgrade autoprefixer from 10.4.20 to 10.4.21.

See this package in npm:
autoprefixer

See this project in Snyk:
https://app.snyk.io/org/d-oit/project/16c67344-4b2f-4e8d-aa74-bbbd15e9cd24?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

package-lock.json

@@ -74,7 +74,7 @@
   "homepage": "https://gethinode.com",
   "dependencies": {
     "@fullhuman/postcss-purgecss": "^7.0.2",
-    "autoprefixer": "^10.4.20",
+    "autoprefixer": "^10.4.21",
     "cssnano": "^7.0.6",
     "cssnano-preset-advanced": "^7.0.6",
     "dotenv": "^16.4.7",