type of dict[Any, Any] is inferred as dict[Unknown, Unknown]

[acidnik]

Description

from typing import Any, reveal_type

def dispatch(data: dict[Any, Any] | list[Any] | Any):
    if isinstance(data, dict):
        reveal_type(data)  # data is dict[Any, Any] | dict[Unknown, Unknown]
    elif isinstance(data, list):
        reveal_type(data)  # same problem here: data is list[Any] | list[Unknown]

Playground:
https://basedpyright.com/?typeCheckingMode=all&reportAny=false&reportExplicitAny=false&reportUnusedParameter=false&code=GYJw9gtgBALgngBwJYDsDmUkQWEMoCCKcANFCAKYBuFAhgDYD68CFAUBwCYXBSdIBnBLRgBjABYAKTiNoAuPklEwA2kVKFiAXSgAfKPUGr1O-eoCUctlBuZeg1AJi0UoitNll%2Byy9dv-KGgZmRHcZZ3M-GwpDewFHZ1cwzwMjX38A6jomFmSIoA

pyright (same problem):
https://pyright-play.net/?code=GYJw9gtgBALgngBwJYDsDmUkQWEMoCCKcAUCQCYCmwU5SAzggIYwDGAFgBTktMBctJKxgBtInAA0hYgF0oAHygAbBqPFzF4gJR8SUfZhoNU9GExStK3XlLrCdeg05CUAbpSZKA%2BvARWeZlqO%2BpQqRvQmZhb%2BNsqqDk7Obh7evjGBQA

expected result: type of data must be the one specified in argument type

[DetachHead]

Any and "Unknown" mean the exact same thing, the only difference is which diagnostics they trigger (more info). if i were making basedpyright from scratch i would never have bothered creating two separate representations of the exact same type.

my guess is the logic that removes redundant types from the union isn't correctly accounting for the fact that Any and Unknown are the same type.

kinda related: #71