Overload missing from createElementNS

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### ⚙ Compilation target

ESNext

### ⚙ Library

6.0.0

### Missing / Incorrect Definition

overload is missing for the `createElementNS` in case provide `"http://www.w3.org/1999/xhtml"` as `namespaceURI`.
```ts
// missing createElementNS(namespaceURI: "http://www.w3.org/1999/xhtml", qualifiedName: K): HTMLElementTagNameMap[K];
createElementNS(namespaceURI: "http://www.w3.org/1999/xhtml", qualifiedName: string): HTMLElement;
createElementNS(namespaceURI: "http://www.w3.org/2000/svg", qualifiedName: K): SVGElementTagNameMap[K];
createElementNS(namespaceURI: "http://www.w3.org/2000/svg", qualifiedName: string): SVGElement;
createElementNS(namespaceURI: "http://www.w3.org/1998/Math/MathML", qualifiedName: K): MathMLElementTagNameMap[K];
```

### Sample Code

```TypeScript
document.createElementNS("http://www.w3.org/1999/xhtml", 'div'); // HTMLElement instead of HTMLDivElement
```

### Documentation Link

_No response_

Start by locating the DOM library declaration for Document.createElementNS and compare its existing namespace-specific overloads. Add the missing XHTML overload shown in the issue, then run the relevant TypeScript library or compiler tests to verify that an XHTML tag such as "div" is inferred as HTMLDivElement rather than HTMLElement.

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