Add JSX.ElementChildrenAttribute change to TypeScript 5.8 release notes

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### 🔎 Search Terms

tsx, jsx, children, 5.8

### 🕗 Version & Regression Information

- This changed between versions 5.7.3 and 5.8
- This changed in commit or PR 60880

### ⏯ Playground Link

_No response_

### 💻 Code

```ts
declare global {
namespace JSX {
type Element = HTMLElement; /* return type for 'jsx()' */

/* accepted element tags & attributes */
type IntrinsicElements = {
/* All HTML elements */
[Tag in keyof HTMLElementTagNameMap]: {
[T in HTMLElementStringAttributes]?: string | Dyn;
} & {
[T in HTMLElementNumberAttributes]?: number | Dyn;
} & (Tag extends keyof TwrlOverrides ? TwrlOverrides[Tag] : {}) & {
style?: string /* note: This should probably be CSSStyleDeclaration */;
// BREAKS HERE without this: children?: Children /* defines the type of children */;
};
};
}
}
```

### 🙁 Actual behavior

The breaking change is not listed in the 5.8 Release Notes

### 🙂 Expected behavior

The breaking change should be listed in the 5.8 Release Notes

### Additional information about the issue

I ran into issues when upgrading TypeScript and narrowed it down to 5.7.3 to 5.8. The issues is that `children` is not inferred by default.

Luckily I came across this discussion: https://github.com/microsoft/TypeScript/issues/61354

This led me to this PR: https://github.com/microsoft/TypeScript/pull/60880

It would have been much faster if the (breaking) change had been mentioned in the [5.8 release notes](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-5-8.html). Moreover, one (apparent?) side effect of #61354 is that `children` does not have a default anymore (i.e. if `JSX.ElementChildrenAttribute` is not set, pre-5.8 `children` would be accepted; post-5.8 not anymore).

Here's the JSX implementation that surfaced the issue for me:

```typescript
declare global {
namespace JSX {
type Element = HTMLElement; /* return type for 'jsx()' */

/* accepted element tags & attributes */
type IntrinsicElements = {
/* All HTML elements */
[Tag in keyof HTMLElementTagNameMap]: {
[T in HTMLElementStringAttributes]?: string | Dyn;
} & {
[T in HTMLElementNumberAttributes]?: number | Dyn;
} & (Tag extends keyof TwrlOverrides ? TwrlOverrides[Tag] : {}) & {
style?: string /* note: This should probably be CSSStyleDeclaration */;
children?: Children /* defines the type of children */; // <- this is now REQUIRED
};
};
}
}
```

Fix: https://github.com/nmattia/twrl/commit/d83fde44202536c52f2816094fdcc4910c945c85#diff-8e3158c55134a198f9c40ac714ce358df04312a9ca77d7726e1813fb2ba5b5c0R34

Review PR 60880 and issue 61354 to confirm the JSX.ElementChildrenAttribute behavior change, then compare it with the TypeScript 5.8 release notes. Update the 5.8 release-notes page to describe the breaking change and its effect on children inference, using the reported twrl example as context.

Written by the indexing model from the issue text.