text: Title: feat: support `msgspec` as another schema definition
  Body: ### Describe the feature
  
  So far, we're using `pydantic` since:
  1. validation
  2. generate OpenAPI JSON schema
  
  Recently, another library called `msgspec` has the same features with a great performance. (pydantic also rewrites the core part with Rust)
  
  We should consider adding `msgspec` as another schema definition.
  
  Refer to https://jcristharif.com/msgspec/jsonschema.html
  
  ### Additional context
  
  _No response_