[BUG] generates broken Python code, default kwarg repeated

[black-snow]

Describe the bug.

I just bumped "@asyncapi/cli": "2.14.1" to "@asyncapi/cli": "2.16.0" and was surprised to see my tests fail, cuz I didn't see any relevant changes in the release notes.

What I found was that there are now serializers and validators, which seems fine, but asyncapi generate models python doc/asyncapi.yaml --pyDantic generates broken code now:

class AnonymousSchema1(BaseModel): 
  id: str = Field()
  source: str = Field()
  specversion: str = Field()
  type: str = Field()
  datacontenttype: Optional[str] = Field(default=None, default=None)
  dataschema: Optional[str] = Field(default=None, default=None)
  subject: Optional[str] = Field(default=None, default=None)
  time: Optional[str] = Field(default=None, default=None)
  data: Optional[Union[dict[str, Any], List[Any], str, float, bool]] = Field(default=None, default=None)
  data_base64: Optional[str] = Field(default=None, default=None)
  additional_properties: Optional[dict[str, Any]] = Field(default=None, exclude=True, default=None)

The kwarg default is repeated everywhere.

(It also has some unused imports, which bugs me a little :D)

Expected behavior

Generates valid Python code.

Screenshots

How to Reproduce

1. grab an asyncapi example spec
2. add a nullable type (I guess), or just $ref https://raw.githubusercontent.com/cloudevents/spec/v1.0.2/cloudevents/formats/cloudevents.json
3. asyncapi generate models python doc/asyncapi.yaml --pyDantic

🥦 Browser

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👀 Have you checked for similar open issues?

• I checked and didn't find similar issue

🏢 Have you read the Contributing Guidelines?

• I have read the Contributing Guidelines

Are you willing to work on this issue ?

Yes I am willing to submit a PR!

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[derberg]

Moved to modelina as model generation comes from here, but to be honest, I don't know why errors are in CLI now as there was no upgrade of modelina CLI in asyncapi CLI for a while

[black-snow]

Glancing over the code I can spot https://github.com/asyncapi/modelina/blob/master/src/generators/python/presets/Pydantic.ts#L53 and https://github.com/asyncapi/modelina/blob/master/src/generators/python/presets/Pydantic.ts#L62 - if I interpret this correctly, it means that this can happen when !property.required && property.property.options.isNullable.

Looks like this bug has been introduced with e9e46b3 two days ago o_Ò
My package-lock lists modelina with 4.0.0+

So the second time default=None is set would only cover the case where !required && !isNullable, which seems just wrong to me. If it's not nullable the default cannot be None (read: null) regardless of whether it's required or not.

Hence, I guess the fix would be to just drop L62-64.