Merge pull request #381 from jenkinsci/dependabot/npm_and_yarn/autoprefixer-10.4.21

Bump autoprefixer from 10.4.20 to 10.4.21

Author: uhafner

package.json

@@ -10,7 +10,7 @@
     "@popperjs/core": "2.11.8"
   },
   "devDependencies": {
-    "autoprefixer": "10.4.20",
+    "autoprefixer": "10.4.21",
     "cross-env": "7.0.3",
     "rtlcss": "4.3.0",
     "sass": "1.86.0",