⬆️ Update dependency postcss-nesting to v13

Author: renovate[bot]

package.json

@@ -49,7 +49,7 @@
     "autoprefixer": "^10.4.15",
     "open-props": "^1.5.15",
     "postcss-jit-props": "^1.0.13",
-    "postcss-nesting": "^12.0.1",
+    "postcss-nesting": "^13.0.0",
     "prettier": "^3.0.3",
     "prettier-plugin-astro": "^0.14.0",
     "typescript": "^5.2.2"