fix: align engines with Rspack v2

Author: chenjiahan

package.json

@@ -51,7 +51,7 @@
     "client"
   ],
   "engines": {
-    "node": ">= 18.12.0"
+    "node": "^20.19.0 || >=22.12.0"
   },
   "packageManager": "pnpm@10.27.0",
   "homepage": "https://rspack.rs",