ParameterSet is private

When using pytest.param to create parameters for a test from a function, that function will return a list of ParameterSet but currently that is only available from _pytest.mark.structures which is private so importing it results in a private import warning.

It would be ideal if this structure was publicly available so developers don't need to disable warnings for uses of pytest.param when using fully hinted code.

The current situation looks like this, which requires a pyright ignore directive to be warning free.

This is simplified example, which could be defined inline but for more complex where the test cases were built by code using a function is more necessary.

from _pytest.mark.structures import ParameterSet  # pyright: ignore[reportPrivateImportUsage]
import pytest

def params() -> list[ParameterSet]:
    return [
        pytest.param("basic", 10, True, id="basic")
        pytest.param("advanced", 5, False, id="advanced")}
    ]


@pytest.mark.parametrize(("val1", "val2", "expected"), params())
async def test_ratelimiter(val1: str, val2: int, expected: bool) -> None:
       """Test code goes here..."""

Ideally this would be public to avoid this, for example:

from pytest.mark.structures import ParameterSet
import pytest

def params() -> list[ParameterSet]:
    return [
        pytest.param("basic", 10, True, id="basic")
        pytest.param("advanced", 5, False, id="advanced")}
    ]


@pytest.mark.parametrize(("val1", "val2", "expected"), params())
async def test_ratelimiter(val1: str, val2: int, expected: bool) -> None:
       """Test code goes here..."""

Start at _pytest.mark.structures and trace the ParameterSet type used by pytest.param. Determine the intended public import path, then verify that type-hinted parameter factories can import it without a private-import warning and that the existing pytest parameterization behavior remains intact.