fix(types): readonly-array as an argument to ref/reactive, inconsistency between type and behaviour

[hubvue]

When readonly-array is used as a ref/reactive parameter, the result type is inconsistent with the behaviour.

example:

export declare function expectType<T>(value: T): void

const refV = ref([ref(1), 2, ref(3), reactive({a: ref(1)})] as const)  // The same goes for reactive


const first = refV.value[0]

console.log((first as any).value) // 1

expectType<number>(refV.value[0])        // it should be error
expectType<Ref<number>>(refV.value[0])   // it should be right

playground

[skirtles-code]

I was wondering whether this change is still required? It seems quite similar to #3820, which was released in 3.2.42.

[hubvue]

@skirtles-code The version of vue that submitted the PR didn't yet support support for readonly arrays, I tested that the current version does, and there's not much use for this PR, so it looks like it's possible to turn this PR off.