Self Checks

• I have read the Contributing Guide and Language Policy.
• This is only for refactoring, if you would like to ask a question, please head to Discussions.
• I have searched for existing issues search for existing issues, including closed ones.
• I confirm that I am using English to submit this report, otherwise it will be closed.
• 【中文用户 & Non English User】请使用英语提交，否则会被关闭 ：）
• Please do not modify this template :) and fill in all the required fields.

Description

class Data(BaseModel):
    ...
    extras: dict = {}

should use Field(default_factory=dict)

Motivation

dict is mutable

Additional Context

No response