ListVariables got result is not sufficient parsed

[witcxc]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

原始配置:

appConfiguration = xxx.xxxAppConfiguration {
    # 应用主进程容器配置，必填
    mainContainer = container.Main {
        readinessProbe = probe_tpl.defaultSofaReadinessProbe
        env : [
            e.Env {
                name: "a"
                value: "b"
            },
        ] + values._envs
    }
}

2. What did you expect to see? (Required)

读取出来的结构如下：

==========appConfiguration==========
  xxx.xxxAppConfiguration-list:0 dict:3 value-len:531
  dict:
  mainContainer
    -list:0 dict:3 value-len:277
    dict:
    readinessProbe
      -list:0 dict:0 value-len:35
    env
      -list:0 dict:0 value-len:73
    envFrom
      -list:1 dict:0 value-len:69
      list:
        -list:0 dict:1 value-len:53
        dict:
        secretRef
          -list:0 dict:0 value-len:18
  resource
    -list:0 dict:0 value-len:14
  image
    -list:0 dict:0 value-len:109

3. What did you see instead (Required)

最后得到的env是一个大string，里面的list和dict都是空

4. What is your KCL components version? (Required)

    kcl-lang.io/kcl-go v0.10.8
    kcl-lang.io/lib v0.10.8

[Peefy]

cc @zong-zhe