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

Author: renovate[bot]

package.json

@@ -21,7 +21,7 @@
     "chokidar": "^3.3.0",
     "dependency-graph": "^1.0.0",
     "picocolors": "^1.0.0",
-    "postcss-load-config": "^5.0.0",
+    "postcss-load-config": "^6.0.0",
     "postcss-reporter": "^7.0.0",
     "pretty-hrtime": "^1.0.3",
     "read-cache": "^1.0.0",