`Symbol.{ dispose, asyncDispose }` have incorrect descriptors

Version

20.4.0

Platform

All

Subsystem

No response

What steps will reproduce the bug?

`Object.getOwnPropertyDescriptor(Symbol, 'dispose');

How often does it reproduce? Is there a required condition?

No response

What is the expected behavior? Why is that the expected behavior?

Object.getOwnPropertyDescriptor(Symbol, 'dispose'); // => {value: Symbol(Symbol.dispose), writable: false, enumerable: false, configurable: false}

All well-known symbols should be non-writable, non-enumerable, and non-configurable to avoid patching and breaking things.

What do you see instead?

Object.getOwnPropertyDescriptor(Symbol, 'dispose'); // => {value: Symbol(Symbol.dispose), writable: true, enumerable: true, configurable: true}

Additional information

No response