feat: support msgspec as another schema definition

[kemingy]

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