tests/test_pydantic.py fails to collect

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### Describe the bug

Not sure when it broke, but currently on FreeBSD, for either yarl 1.24.2 and 1.24.5, `tests/test_pydantic.py` fails to collect:

```
============================= test session starts ==============================
platform freebsd15 -- Python 3.12.14, pytest-9.1.1, pluggy-1.6.0 -- /usr/local/bin/python3.12
codspeed: 5.0.3 (disabled, mode: walltime, callgraph: not supported, timer_resolution: 280.0ns)
cachedir: .pytest_cache
hypothesis profile 'default'
rootdir: /work/usr/ports/www/py-yarl/work-py312/yarl-1.24.5
configfile: pytest.ini
testpaths: tests/
plugins: codspeed-5.0.3, hypothesis-6.165.10
collecting ... collected 1621 items / 1 error

==================================== ERRORS ====================================
___________________ ERROR collecting tests/test_pydantic.py ____________________
tests/test_pydantic.py:13: in
class TstModel(pydantic.BaseModel):
/usr/local/lib/python3.12/site-packages/pydantic/main.py:197: in __new__
fields[ann_name] = ModelField.infer(
/usr/local/lib/python3.12/site-packages/pydantic/fields.py:504: in infer
return cls(
/usr/local/lib/python3.12/site-packages/pydantic/fields.py:434: in __init__
self.prepare()
/usr/local/lib/python3.12/site-packages/pydantic/fields.py:555: in prepare
self.populate_validators()
/usr/local/lib/python3.12/site-packages/pydantic/fields.py:829: in populate_validators
*(get_validators() if get_validators else list(find_validators(self.type_, self.model_config))),
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/usr/local/lib/python3.12/site-packages/pydantic/validators.py:768: in find_validators
raise RuntimeError(f'no validator found for {type_}, see `arbitrary_types_allowed` in Config')
E RuntimeError: no validator found for , see `arbitrary_types_allowed` in Config
!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
=============================== 1 error in 1.38s ===============================
```

Pydanyic version is 1.10.20. Full build log (including all versions of dependencies) here: https://gist.github.com/AMDmi3/6eac3b8045f644ed96890aaa36281bbb

### To Reproduce

Run pytest

### Expected behavior

Test should pass

### Python Version

```console
3.12.14
```

### multidict Version

```console
6.7.1
```

### propcache Version

```console
0.4.1
```

### yarl Version

```console
1.24.5
```

### OS

FreeBSD 15.1

### Additional context

_No response_

Start by running pytest on tests/test_pydantic.py with Python 3.12, yarl 1.24.5, and Pydantic 1.10.20 to reproduce the collection error. Inspect the TstModel definition and its interaction with Pydantic, then run the test file and the full suite to confirm collection succeeds and the tests pass.

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