add missing phantom dependency to fix pnpm build

Author: mgyarmathy

package-lock.json

@@ -109,6 +109,7 @@
         "@types/eslint__js": "^8.42.3",
         "@types/eventsource": "^1.1.15",
         "@types/express": "^5.0.0",
+        "@types/express-serve-static-core": "^5.1.0",
         "@types/node": "^22.0.2",
         "@types/supertest": "^6.0.2",
         "@types/ws": "^8.5.12",