Bump postcss to ^8.5.8 (#4268)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

docs/package.json

@@ -39,7 +39,7 @@
     "lz-string": "^1.5.0",
     "match-sorter": "^8.2.0",
     "next": "16.1.6",
-    "postcss": "^8.5.6",
+    "postcss": "^8.5.8",
     "postcss-custom-media": "^12.0.1",
     "postcss-import": "^16.1.1",
     "radix-ui": "^1.4.3",