Update dependency @types/mocha to v9

Author: renovate-bot

package.json

@@ -65,7 +65,7 @@
     "@types/eslint": "^7.2.10",
     "@types/eslint-scope": "^3.7.0",
     "@types/eslint-visitor-keys": "^1.0.0",
-    "@types/mocha": "^8.2.2",
+    "@types/mocha": "^9.0.0",
     "@types/node": "^15.0.1",
     "@typescript-eslint/eslint-plugin": "^4.22.0",
     "@typescript-eslint/parser": "^4.22.0",