Simplify types with ReadonlyArray only

[JounQin]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and discussions and couldn’t find anything or linked relevant results below
• I made sure the docs are up to date
• I included tests (or that’s not needed)

Description of changes

ReadonlyArray also covers Array already.

TypeScript Playground

[Copilot]

Pull Request Overview

This PR simplifies TypeScript type definitions by removing redundant Array type annotations, since ReadonlyArray already covers Array types in TypeScript's type system.

• Removed duplicate Array<Props | TestFunction | string> from the Test typedef
• Removed redundant Array<string> overload from the type annotation

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[wooorm]

Hmm, it makes some sense. Verified with:

const a: Array<number> = [1]

function x(y: ReadonlyArray<number>) {
  console.log(y)
}

a.push(2)

x(a)

a.push(3)