`sentinel`s incompatible with `TypeForm`

[Viicos]

Describe the Bug

from typing_extensions import TypeForm, reveal_type, sentinel

MISSING = sentinel('MISSING')

class A[T]:
    def __init__(self, t: TypeForm[T])-> None: ...


# Argument `MISSING` is not assignable to parameter `t` with type `TypeForm[@_]` in function `A.__init__`
a = A(MISSING)

reveal_type(a)  # A[Unknown]

Sandbox Link

https://pyrefly.org/sandbox/?project=v2.pZQ7C8IwFIX_yoUOqUuzO9lFcVAEdVIxRUMt6o208fHzPbcvLKIIriH3_Z3zg2Vu7cNblpFa8cvNhy4_d8wHAFn2GduTHGkyns_H0xGabl5DVb-p8oqVGOPVYvNZib7flsK_XgMTRVEkKdYcUJyn1zMqkKmzG1EAViimiZ2KyZF3OFkOuuB1ZLyhe-YPMp4l0xYYbDeI5VZ_ZOKo6ccAbYwSh3WRcoKX2cOkR4RmVks-srszDv3OR0Cz6oHqVcMZAVZ6hf-iHkYKYL2WDt5fir7WTbjLU21Z792u0J0ITSKF5JZkpat305EreS6Q9h8wVcWl-oalEirx4ytpTw

(Only applicable for extension issues) IDE Information

version 1.2.0