Bump postcss from 8.4.8 to 8.4.12

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.8 to 8.4.12.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.8...8.4.12)

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

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

Author: dependabot[bot]

package-lock.json

@@ -18,7 +18,7 @@
 		"css-loader": "^6.7.1",
 		"json-loader": "0.5.7",
 		"mini-css-extract-plugin": "^2.6.0",
-		"postcss": "^8.4.8",
+		"postcss": "^8.4.12",
 		"postcss-loader": "^6.2.1",
 		"postcss-nested": "^5.0.6",
 		"postcss-preset-env": "^7.4.2",