Bump autoprefixer from 9.8.5 to 9.8.6 (#1538)

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 9.8.5 to 9.8.6.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/master/CHANGELOG.md)
- [Commits](https://github.com/postcss/autoprefixer/compare/9.8.5...9.8.6)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

package.json

@@ -23,7 +23,7 @@
     "test": "npm run prettier:check && npm run xo"
   },
   "devDependencies": {
-    "autoprefixer": "^9.8.5",
+    "autoprefixer": "^9.8.6",
     "eslint-plugin-compat": "^3.8.0",
     "postcss-cli": "^7.1.2",
     "prettier": "2.0.4",