chore(deps): bump koa from 2.16.1 to 3.0.0 in /examples/openid-connect

Bumps [koa](https://github.com/koajs/koa) from 2.16.1 to 3.0.0.
- [Release notes](https://github.com/koajs/koa/releases)
- [Changelog](https://github.com/koajs/koa/blob/master/History.md)
- [Commits](koajs/koa@v2.16.1...v3.0.0)

---
updated-dependencies:
- dependency-name: koa
  dependency-version: 3.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

examples/openid-connect/package.json

@@ -13,7 +13,7 @@
     "@koa/router": "^13.0.0",
     "@slack/web-api": "^7.3.4",
     "jsonwebtoken": "^9.0.2",
-    "koa": "^2.13.1",
+    "koa": "^3.0.0",
     "uuid": "^11.0.2"
   }
 }