fix: add xmlns attribute to HTMLAttributes type (#16080)

* Add `xmlns` attribute to HTMLAttributes type

The `xmlns` attribute is not only allowed on SVG elements, but on all HTML elements.

* move to DOMAttributes

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>

Author: christophsanz

.changeset/metal-rivers-laugh.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: move xmlns attribute from SVGAttributes to to DOMAttributes

packages/svelte/elements.d.ts

@@ -463,6 +463,8 @@ export interface DOMAttributes<T extends EventTarget> {
 	'on:fullscreenerror'?: EventHandler<Event, T> | undefined | null;
 	onfullscreenerror?: EventHandler<Event, T> | undefined | null;
 	onfullscreenerrorcapture?: EventHandler<Event, T> | undefined | null;
+
+	xmlns?: string | undefined | null;
 }
 
 // All the WAI-ARIA 1.1 attributes from https://www.w3.org/TR/wai-aria-1.1/
@@ -1809,7 +1811,6 @@ export interface SVGAttributes<T extends EventTarget> extends AriaAttributes, DO
 	'xlink:type'?: string | undefined | null;
 	'xml:base'?: string | undefined | null;
 	'xml:lang'?: string | undefined | null;
-	xmlns?: string | undefined | null;
 	'xmlns:xlink'?: string | undefined | null;
 	'xml:space'?: string | undefined | null;
 	y1?: number | string | undefined | null;