chore(deps): update dependency @types/mocha to v9 (#264)

Author: renovate-bot

packages/google-cloud-bigquery-storage/package.json

@@ -30,7 +30,7 @@
     "google-gax": "^3.0.1"
   },
   "devDependencies": {
-    "@types/mocha": "^8.0.0",
+    "@types/mocha": "^9.0.0",
     "@types/node": "^16.0.0",
     "@types/sinon": "^10.0.0",
     "c8": "^7.1.0",