chore(deps-dev): update @types/node requirement from ^20.5.7 to ^20.8.0

Updates the requirements on [@types/node](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/node) to permit the latest version.
- [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
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -34,7 +34,7 @@
     "@types/chai-as-promised": "^7.1.6",
     "@types/gulp": "^4.0.14",
     "@types/mocha": "^9.1.1",
-    "@types/node": "^20.5.7",
+    "@types/node": "^20.8.0",
     "@types/proxyquire": "^1.3.29",
     "@types/sinon": "^10.0.17",
     "@types/sinon-chai": "^3.2.10",