feat: upgrade @octokit/webhooks from 10.6.0 to 13.3.0

Snyk has created this PR to upgrade @octokit/webhooks from 10.6.0 to 13.3.0.

See this package in npm:
@octokit/webhooks

See this project in Snyk:
https://app.snyk.io/org/cachiman/project/83341dfb-aebc-4510-8ce6-6b88252e70b1?utm_source=github-cloud-app&utm_medium=referral&page=upgrade-pr

packages/release-please/package.json

@@ -33,7 +33,7 @@
     "@google-automations/issue-utils": "^3.0.0",
     "@google-automations/label-utils": "^4.0.0",
     "@octokit/rest": "^19.0.4",
-    "@octokit/webhooks": "^10.1.5",
+    "@octokit/webhooks": "^13.3.0",
     "gcf-utils": "^15.0.0",
     "jsonwebtoken": "^9.0.0",
     "release-please": "^16.0.0"