📦 Update dependency @octokit/rest to v21

Author: renovate[bot]

onduty/package-lock.json

@@ -17,7 +17,7 @@
   },
   "license": "Apache-2.0",
   "dependencies": {
-    "@octokit/rest": "20.1.1",
+    "@octokit/rest": "21.0.0",
     "@probot/serverless-gcf": "0.2.0",
     "dotenv": "16.4.5",
     "http-status-codes": "2.3.0",