chore(deps): replace dependency @tsconfig/node18 with @tsconfig/node20

Author: renovate[bot]

package.json

@@ -47,7 +47,7 @@
   "license": "MIT",
   "devDependencies": {
     "@openapitools/openapi-generator-cli": "^2.7.0",
-    "@tsconfig/node18": "^18.0.0",
+    "@tsconfig/node20": "^20.1.0",
     "@types/jsdom": "^27.0.0",
     "@types/node": "^22.18.1",
     "@typescript-eslint/eslint-plugin": "^8.42.0",