chore(deps-dev): bump postcss from 8.5.3 to 8.5.6

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.6
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

package-lock.json

@@ -128,7 +128,7 @@
     "mini-css-extract-plugin": "^2.7.6",
     "node-loader": "^2.0.0",
     "patch-package": "^8.0.0",
-    "postcss": "^8.5.3",
+    "postcss": "^8.5.6",
     "postcss-loader": "^7.3.3",
     "postcss-preset-mantine": "^1.17.0",
     "postcss-simple-vars": "^7.0.1",