fix(deps): update dependency postcss-load-config to v6

Author: renovate[bot]

package.json

@@ -74,7 +74,7 @@
     "esutils": "^2.0.3",
     "known-css-properties": "^0.31.0",
     "postcss": "^8.4.38",
-    "postcss-load-config": "^3.1.4",
+    "postcss-load-config": "^6.0.0",
     "postcss-safe-parser": "^6.0.0",
     "postcss-selector-parser": "^6.0.16",
     "semver": "^7.6.0",