Bump autoprefixer from 9.8.0 to 9.8.6

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 9.8.0 to 9.8.6.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/master/CHANGELOG.md)
- [Commits](postcss/autoprefixer@9.8.0...9.8.6)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -18,7 +18,7 @@
   "homepage": "https://github.com/google/docsy-example#readme",
   "dependencies": {},
   "devDependencies": {
-    "autoprefixer": "^9.8.0",
+    "autoprefixer": "^9.8.6",
     "postcss-cli": "^7.1.1"
   }
 }