Instance attribute should take precedence over non-data descriptors in attribute writes

[grievejia]

Describe the Bug

Minimal repro:

class NonDataDescriptor:
    def __get__(self, instance: object, owner: type | None = None) -> str:
        return "derp"

class C:
    x = NonDataDescriptor()

    def f(self):
        self.x = 1  # This is okay

Expected: No error
Actual: Attribute x of class C is a read-only descriptor with no __set__ and cannot be set

Sandbox Link

https://pyrefly.org/sandbox/?code=MYGwhgzhAEByD2A7AImALmZBTCwBOAlgA5rx4BcAUNDdACZYBm0A+iwOZZpsAUEWIRgBpoBRBAyJgWctHgAjAFZZgaEfADuiLBWhoAnkSzQAPnCTGAvOe0BKaAFoAfNAkVqtT3i4BXPImgAIgY8IkDKSlBIGABhKk8AD2hrBBR0TBx8YlI8HlsIzwZmRj4BRlt4z1p+QQA6JOsARhoAYmgAFQALAhgeuQBrMH0gA

(Only applicable for extension issues) IDE Information

No response