chore(deps): update commitlint monorepo to v9 (#26)

Co-authored-by: Renovate Bot <[email protected]>

Author: renovate[bot]

package.json

@@ -40,8 +40,8 @@
     "url": "https://github.com/netlify-labs/netlify-plugin-lighthouse/issues"
   },
   "devDependencies": {
-    "@commitlint/cli": "^8.1.0",
-    "@commitlint/config-conventional": "^8.1.0",
+    "@commitlint/cli": "^9.0.0",
+    "@commitlint/config-conventional": "^9.0.0",
     "@semantic-release/changelog": "^5.0.1",
     "@semantic-release/git": "^9.0.0",
     "eslint": "^7.0.0",