Bug: Examples in union types are not found when using coverage

Description

For union types where one of the subtypes are annotated with examples I'd expect those examples to be used when generating values from that subtype.

This works for .build() and .batch(), but breaks when generating coverage.

MCVE

from typing import Annotated

import pydantic
from polyfactory.factories.pydantic_factory import ModelFactory
from pydantic import AfterValidator, Field

the_list = ["foo", "bar", "baz"]  # Some dynamically populated list


def l_validator(v):
    if v not in the_list:
        raise ValueError(f"{v} not in {the_list}")
    return v


TheListType = Annotated[str, AfterValidator(l_validator), Field(examples=the_list)]


class WithoutNone(pydantic.BaseModel):
    f: TheListType


class WithNone(pydantic.BaseModel):
    f: TheListType | None


class WithoutNoneFactory(ModelFactory[WithoutNone]):
    __check_model__ = True
    __use_examples__ = True


class WithNoneFactory(ModelFactory[WithNone]):
    __check_model__ = True
    __use_examples__ = True

# These three works fine
print("Without, batch:", WithoutNoneFactory.batch(2))
print("With, batch:", WithNoneFactory.batch(2))
print("Without, coverage:", list(WithoutNoneFactory.coverage()))
# Breaks here
print("With, coverage:", list(WithNoneFactory.coverage()))

Logs

Without, batch: [WithoutNone(f='bar'), WithoutNone(f='bar')]
With, batch: [WithNone(f='bar'), WithNone(f=None)]
Without, coverage: [WithoutNone(f='foo'), WithoutNone(f='bar'), WithoutNone(f='baz')]
Traceback (most recent call last):
...
pydantic_core._pydantic_core.ValidationError: 1 validation error for WithNone
f
  Value error, JtYDrNsNdqcQNeGCBrfN not in ['foo', 'bar', 'baz'] [type=value_error, input_value='JtYDrNsNdqcQNeGCBrfN', input_type=str]
    For further information visit https://errors.pydantic.dev/2.13/v/value_error

Release Version

3.3.0

Platform

• Linux
• Mac
• Windows
• Other (Please specify in the description above)

Start with the ModelFactory.coverage() path and reproduce the supplied MCVE using Pydantic's Annotated, AfterValidator, and Field examples. Done means coverage for the optional union returns the annotated example values instead of generating an invalid value, while the existing batch and non-union coverage cases remain working.