[flake8-pyi] Make example error out-of-the-box (PYI059)

[MeGaGiGaGon]

Summary

Part of #18972

This PR makes generic-not-last-base-class (PYI059)'s example error out-of-the-box

Warning

This PR has more extensive and possibly wrong changes than my usual "Make example error out-of-the-box" PRs

I made fairly lengthy modifications so that the example is valid code (adding the collections.abc imports and TypeVars), but all PYI059 actually needs to trigger is a from typing import Generic. I'm not sure if this is right choice, since I'm uncertain if the examples being working code is favored vs verbosity.

I also changed the Tuple to tuple since in modern python that would require importing the deprecated alias, but it's also not nessacary for PYI059 to trigger.

Old example

class LinkedList(Generic[T], Sized):
    def push(self, item: T) -> None:
        self._items.append(item)

class MyMapping(
    Generic[K, V],
    Iterable[Tuple[K, V]],
    Container[Tuple[K, V]],
):
    ...

New example

from collections.abc import Container, Iterable, Sized
from typing import Generic, TypeVar


T = TypeVar("T")
K = TypeVar("K")
V = TypeVar("V")


class LinkedList(Generic[T], Sized):
    def push(self, item: T) -> None:
        self._items.append(item)


class MyMapping(
    Generic[K, V],
    Iterable[tuple[K, V]],
    Container[tuple[K, V]],
):
    ...

The "use instead" section was also modified similarly

Test Plan

N/A, no functionality/tests affected

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

[AlexWaygood]

Thanks, this makes sense to me!