Bump engine.io from 6.4.1 to 6.4.2 in /TestServer

Bumps [engine.io](https://github.com/socketio/engine.io) from 6.4.1 to 6.4.2.
- [Release notes](https://github.com/socketio/engine.io/releases)
- [Changelog](https://github.com/socketio/engine.io/blob/main/CHANGELOG.md)
- [Commits](https://github.com/socketio/engine.io/compare/6.4.1...6.4.2)

---
updated-dependencies:
- dependency-name: engine.io
  dependency-type: indirect
...

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

TestServer/package-lock.json

@@ -8922,8 +8922,9 @@
             }
         },
         "../CommonServer/node_modules/engine.io": {
-            "version": "6.4.1",
-            "license": "MIT",
+            "version": "6.4.2",
+            "resolved": "https://registry.npmjs.org/engine.io/-/engine.io-6.4.2.tgz",
+            "integrity": "sha512-FKn/3oMiJjrOEOeUub2WCox6JhxBXq/Zn3fZOMCBxKnNYtsdKjxhl7yR3fZhM9PV+rdE75SU5SYMc+2PGzo+Tg==",
             "dependencies": {
                 "@types/cookie": "^0.4.1",
                 "@types/cors": "^2.8.12",