dict type incorrectly converted (widened?) to object via TypeVar and overload

Bug Report

In the snippet below I'd expect the revealed type to be def () -> typing.Awaitable[builtins.dict], not def () -> typing.Awaitable[builtins.object].

To Reproduce

from typing import *


P = ParamSpec("P")
T = TypeVar("T")

@overload
def ensure_async(f: Callable[P, Awaitable[T]])-> Callable[P, Awaitable[T]]: ...

@overload
def ensure_async(f: Callable[P, T])-> Callable[P, Awaitable[T]]: ...

def ensure_async(f):
   ...
        
async def a() -> None:
    g: Callable[[], dict] | Callable[[], Awaitable[dict]]
    reveal_type(ensure_async(g))

https://mypy-play.net/?mypy=master&python=3.12&gist=f596993883d9235e669e38dbe212909e

Actual Behavior

main.py:18: note: Revealed type is "def () -> typing.Awaitable[builtins.object]"

Your Environment

• Mypy version used: 1.6 or master
• Mypy command-line flags:
• Mypy configuration options from mypy.ini (and other config files):
• Python version used: 3.12

This may be related to https://github.com/python/mypy/issues/12385 - closest issue I can find.

Inizia con il riproduttore Python fornito in mypy-play e conferma il tipo rivelato nella versione corrente di mypy. Traccia la risoluzione degli overload e l’inferenza di TypeVar per l’unione di firme Callable; il lavoro è completo quando il risultato viene riportato come Callable[[], Awaitable[dict]] anziché Awaitable[object], con un test di regressione che copra il caso.