<math> wrongly typed as Element instead of MathMlElement

[jelhan]

Glint types <math> as Element. It should be the more specific MathMlElement.

This is an issue in some cases. E.g. Element does not implement ElementCSSInlineStyle, which MathMlElement does. This breaks usage of ember-style-modifier on <math> elements as documented by this failing test: jelhan/ember-style-modifier#237

There is already a special handing for SVGElement in Glint:

glint/packages/template/-private/dsl/types.d.ts

Lines 7 to 17 in 01b8deb

	/**
	* Given a tag name, returns an appropriate `Element` subtype.
	* NOTE: This will return a union for elements that exist both in HTML and SVG. Technically, this will be too permissive.
	*/
	export type ElementForTagName<Name extends string> = Name extends keyof HTMLElementTagNameMap
	? Name extends keyof SVGElementTagNameMap
	? HTMLElementTagNameMap[Name] & SVGElementTagNameMap[Name]
	: HTMLElementTagNameMap[Name]
	: Name extends keyof SVGElementTagNameMap
	? SVGElementTagNameMap[Name]
	: Element;

This needs to be extended to cover MathMlElement as well.