Update dependency stylelint-config-prettier to v9

Author: renovate[bot]

package.json

@@ -65,7 +65,7 @@
     "postcss-nesting": "^7.0.1",
     "prettier": "^1.19.1",
     "stylelint": "^15.10.1",
-    "stylelint-config-prettier": "^8.0.2",
+    "stylelint-config-prettier": "^9.0.0",
     "stylelint-prettier": "^1.2.0",
     "upgradeps": "^2.0.6",
     "vinyl-buffer": "^1.0.1",