BaseModel with defer_build breaks with TypeAdapter.

[zakstucke]

Initial Checks

• I confirm that I'm using Pydantic V2

Description

Repeated uses of a TypeAdapter with a model breaks when using defer_build.

Traceback (most recent call last):
  File "/ptest.py", line 40, in <module>
    ta.validate_python({"foo": "str"})
  File "/venv/lib/python3.11/site-packages/pydantic/type_adapter.py", line 283, in validate_python
    return self.validator.validate_python(__object, strict=strict, from_attributes=from_attributes, context=context)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.11/site-packages/pydantic/_internal/_mock_val_ser.py", line 47, in __getattr__
    raise PydanticUserError(self._error_message, code=self._code)
pydantic.errors.PydanticUserError: `Foo` is not fully defined; you should define all referenced types, then call `Foo.model_rebuild()`.

For further information visit **https://errors.pydantic.dev/2.4/u/class-not-fully-defined**

Example Code

from pydantic import BaseModel, TypeAdapter

class Foo(BaseModel):
    foo: str
    model_config = {
        "defer_build": True,
    }


ta = TypeAdapter(Foo)
ta.validate_python({"foo": "str"})
ta.validate_python({"foo": "str"}) # <--- Second call breaks

Python, Pydantic & OS Version

pydantic version: 2.4.2
        pydantic-core version: 2.10.1
          pydantic-core build: profile=release pgo=true
                 install path: /venv/lib/python3.11/site-packages/pydantic
               python version: 3.11.5 (main, Aug 25 2023, 13:19:50) [GCC 11.4.0]
                     platform: Linux-6.2.0-33-generic-x86_64-with-glibc2.35
             related packages: email-validator-2.0.0 mypy-1.5.1 fastapi-0.103.2 typing_extensions-4.8.0

[Kludex]

Thanks for the report. Yeah, it does look like a bug.

[sydney-runkle]

@zakstucke,

Thanks for the report! We've pushed a fix that'll become active with the next release 😄.