Bump postcss from 8.4.7 to 8.4.8

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.7 to 8.4.8.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.4.7...8.4.8)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

package.json

@@ -26,7 +26,7 @@
   "devDependencies": {
     "autoprefixer": "^10.4.2",
     "eslint-plugin-compat": "^4.0.2",
-    "postcss": "^8.4.7",
+    "postcss": "^8.4.8",
     "postcss-cli": "^9.1.0",
     "prettier": "2.5.1",
     "xo": "^0.48.0"