Make arbitrary_types_allowed default to True with dataclass decorator

[jzwick-narmi]

from the docs:

pydantic.dataclasses.dataclass is a drop-in replacement for dataclasses.dataclass with validation

But needing to define a config and pass it to all my already defined dataclasses in order for them to work out of the box makes it strictly not a drop-in replacement. Plus, I don't see why this would be restricted to begin with, why would it be useful NOT to allow arbitrary class types? Seems niche to me.

If there is no interest in defaulting toTrue here, perhaps update the documentation with this caveat.

[rusheb]

For anybody who (like me) came here trying to figure out how to set arbitrary_types_allowed for pydantic dataclasses, the solution/workaround is to use the config parameter:

from pydantic import ConfigDict
from pydantic.dataclasses import dataclass

class MyClass:
    pass

@dataclass(config=ConfigDict(arbitrary_types_allowed=True))
class MyPydanticDataclass:
    a: MyClass