static typecheck error in pytest-mypy-plugins pipeline: pytest 8.3.0 renamed _TracebackStyle to TracebackStyle

[mjpieters]

Pytest renamed _pytest._code.code._TracebackStyle to _pytest._code.code.TracebackStyle in version 8.3.0, which means that the mypy checks in pipelines here now fail with:

pytest_mypy_plugins/item.py:22: error: Module "_pytest._code.code" has no attribute "_TracebackStyle"; maybe "TracebackStyle", "TracebackType", or "TracebackEntry"? [attr-defined]

You can't work around this renaming in static type checks (there is no recognised syntax for a type checker to change an import statically), so the only work-around is to not import that name until pytest 8.3.0 is the minimum requirement for this project.

I'd instead just define it locally:

if TYPE_CHECKING:
    # pytest 8.3.0 renamed _TracebackStyle to TracebackStyle, but there is no syntax
    # to assert what version you have using static conditions, so it has to be
    # manually re-defined here. Once minimum supported pytest version is >= 8.3.0,
    # the following can be replaced with `from _pytest._code.code import TracebackStyle`
    TracebackStyle = Literal["long", "short", "line", "no", "native", "value", "auto"]

(I renamed _TracebackStyle to TracebackStyle to make it easier to switch later).