Alias that is generic over a ParamSpec is not hashable when using a list as parameters_expression

Bug report

Bug description:

This is slightly related to #124445, but a different issue, maybe it can be solved at the same time?

Consider the following code where [T] is a parameters_expression according to PEP 612. Similar to using Callable or using Generic[P] or Protocol[P] I would expect the following code to work and receive a hashable variable:

from typing import TypeVar
from collections.abc import Callable
type X[**P] = Callable[P, int]
T = TypeVar("T")
hash(X[[T]])
# ~~~~^^^^^^^^
# TypeError: unhashable type: 'list'

Cause:

The problem is that X[[T]].__args__ == ([T],) which cannot be hashed. I think the list should either be turned into a tuple. Either a nested one as its done for Generic and Protocol or joined like for Callable[P, str][[int]].__args__.

Discussion:

I've opened a parallel topic on discuss

CPython versions tested on:

3.13.0.rc2

Operating systems tested on:

Linux

EDIT: A thought, should this be changed for whole class in general?

Issue の再現コードから始め、ParamSpec エイリアスの動作を、参照されている Generic、Protocol、Callable のケースと比較してください。リストパラメーターをネストしたタプルにするべきか、結合するべきかを判断するために、PEP 612、issue #124445、およびリンクされたディスカッションを読んでください。hash(X[[T]]) が hash 化できないリストなしで動作し、意図された引数を保持できれば完了です。