Inconsistent behavior with Generic ElementType

### 🔎 Search Terms

JSX, Generic ElementType, TS2786

### 🕗 Version & Regression Information

- Behavior seen in 5.8.3 and 5.9.0-dev.20250703
- I was unable to test this on prior versions

### ⏯ Playground Link

_No response_

### 💻 Code

```ts
export namespace dsl {
export namespace JSX {
export type Element = {
name: U
type: string
children: Element[]
}

[tsconfig.json](https://github.com/user-attachments/files/21047590/tsconfig.json)

export function createElement(
tag: JSX.ElementType,
props : { name: U },
...children: JSX.Element[]
): JSX.Element {
return tag(props, ...children)
}
}

function Form(props: { name: U }, ...children: dsl.JSX.Element[]) {
return { ...props, type: "form", children }
}

const formDesugared = dsl.createElement(
Form, { name: "one" }
)

const form = (
// <--- Error here, error TS2786: 'Form' cannot be used as a JSX component.
)

```

### 🙁 Actual behavior

Compile error:

sui.tsx:31:6 - error TS2786: 'Form' cannot be used as a JSX component.
Its type '(props: { name: U; }, ...children: Element[]) => { type: string; children: Element[]; name: U; }' is not a valid JSX element type.
Types of parameters 'props' and 'props' are incompatible.
Type '{ name: unknown; }' is not assignable to type '{ name: string; }'.
Types of property 'name' are incompatible.
Type 'unknown' is not assignable to type 'string'.

31

### 🙂 Expected behavior

Changing props: { name: U } in the definition of ElementType to props: { name: string } causes the code to compile [loosing the wanted typing of the resulting Element

Since the desugared version of the code compiles and infers types correctly, I'd expect the JSX code to compile, or at least produce a less deeply mysterious error - the type of the 'name' property plainly *isn't* unknown.

### Additional information about the issue

_No response_

リンクされた tsconfig.json を使って .tsx の例を TypeScript 5.8.3 と 5.9 の開発版で再現し、JSX と dsl.createElement、および診断 TS2786 を比較します。JSX.ElementType がジェネリック Form をどのようにチェックするかを追跡します。完了条件は、JSX 形式がデシュガーされた呼び出しと一貫してコンパイルされ、意図した推論済みの Element の型付けを保持し、誤解を招く未知の名前エラーを回避することです。

索引モデルが issue の本文から書いたものです。