Bump autoprefixer from 9.8.6 to 9.8.7

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 9.8.6 to 9.8.7.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/9.8.7/CHANGELOG.md)
- [Commits](https://github.com/postcss/autoprefixer/compare/9.8.6...9.8.7)

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

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

package.json

@@ -12,7 +12,7 @@
   "devDependencies": {
     "@babel/core": "^7.15.5",
     "@babel/preset-env": "^7.15.6",
-    "autoprefixer": "^9.8.6",
+    "autoprefixer": "^9.8.7",
     "braces": "^3.0.2",
     "browser-sync": "^2.27.5",
     "child_process": "^1.0.2",