Bump @types/node from 18.15.11 to 20.8.9

Bumps [@types/node](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/node) from 18.15.11 to 20.8.9.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/node)

---
updated-dependencies:
- dependency-name: "@types/node"
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

package.json

@@ -55,7 +55,7 @@
     "@types/eventsource": "^1.1.11",
     "@types/express": "^4.17.13",
     "@types/jest": "^29.5.3",
-    "@types/node": "18.15.11",
+    "@types/node": "20.8.9",
     "@types/supertest": "^2.0.11",
     "@typescript-eslint/eslint-plugin": "^5.0.0",
     "@typescript-eslint/parser": "^5.62.0",