Bump postcss from 8.1.10 to 8.1.12

Bumps [postcss](https://github.com/postcss/postcss) from 8.1.10 to 8.1.12.
- [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/8.1.10...8.1.12)

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

package.json

@@ -62,7 +62,7 @@
   "lint-staged": "^10.5.2",
   "mini-css-extract-plugin": "^1.3.1",
   "npm-run-all": "^4.1.5",
-  "postcss": "^8.1.10",
+  "postcss": "^8.1.12",
   "postcss-loader": "^4.1.0",
   "prettier": "^2.2.1",
   "release-it": "^14.2.2",