[Bug] Multi-level inheritance is not working

[steeling]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

The below returns an error, but works when the last commented line is uncommented

schema Metadata:
  environment: str
  region: str
  name: str

schema MySchema1:
  metadata: Metadata

schema MySchema2(MySchema1):
  metadata.environment = "dev"

schema MySchema3(MySchema2):
  metadata.region = "us-east-1"

output = MySchema3 {
  metadata.name = "hello"
  # uncomment the next line to make this work, but I shouldn't have to, as it should be inherited.
  # metadata.environment = "dev"
}

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

I expected the output

output:
  metadata:
    environment: dev
    region: us-east-1
    name: hello

3. What did you see instead (Required)

attribute 'environment' of Metadata is required and can't be None or Undefined

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

kpm 0.3.6

[Peefy]

We have fixed it in #787, it will be released in version 0.6.1 of kcl. You can refer to it and indicate if there are any further issues. Thank you! ❤️