update @types/node requirement from ^20.4.2 to ^20.8.0

---
updated-dependencies:
- dependency-name: "@types/node"
  dependency-type: direct:development
...

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

package.json

@@ -47,7 +47,7 @@
     "@types/chai-as-promised": "^7.1.5",
     "@types/gulp": "^4.0.13",
     "@types/mocha": "^10.0.1",
-    "@types/node": "^20.4.2",
+    "@types/node": "^20.8.0",
     "@types/proxyquire": "^1.3.28",
     "@types/sinon": "^10.0.15",
     "@types/sinon-chai": "^3.2.9",