Bump postcss from 8.4.6 to 8.4.12

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.6 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@8.4.6...8.4.12)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -31,7 +31,7 @@
     "eslint-plugin-nuxt": "^3.1.0",
     "eslint-plugin-prettier": "^4.0.0",
     "jest": "^27.5.1",
-    "postcss": "^8.4.6",
+    "postcss": "^8.4.12",
     "prettier": "^2.6.0",
     "vue-jest": "^3.0.7",
     "@braid/vue-formulate": "^2.5.3",