Bump autoprefixer from 9.8.6 to 10.0.0

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 9.8.6 to 10.0.0.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/master/CHANGELOG.md)
- [Commits](postcss/autoprefixer@9.8.6...10.0.0)

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

package.json

@@ -43,7 +43,7 @@
   "homepage": "https://github.com/bcomnes/bret.io#readme",
   "devDependencies": {
     "@tap-format/spec": "^0.2.0",
-    "autoprefixer": "^9.0.0",
+    "autoprefixer": "^10.0.0",
     "cpx2": "^2.0.0",
     "dependency-check": "^4.1.0",
     "generate-feed": "^1.1.13",