Remove deprecated `lwc.buildCustomElementConstructor` API

[nolanlawson]

This API is deprecated in favor of Ctor.CustomElementConstructor and it has roughly zero usage. We should just remove it.

lwc/packages/@lwc/engine-dom/src/apis/build-custom-element-constructor.ts

Lines 41 to 53 in d10cdb0

	export function deprecatedBuildCustomElementConstructor(
	Ctor: ComponentConstructor
	): HTMLElementConstructor {
	if (process.env.NODE_ENV !== 'production') {
	/* eslint-disable-next-line no-console */
	console.warn(
	'Deprecated function called: "buildCustomElementConstructor" function is deprecated and it will be removed.' +
	`Use "${Ctor.name}.CustomElementConstructor" static property of the component constructor to access the corresponding custom element constructor instead.`
	);
	}
	return Ctor.CustomElementConstructor;
	}

[git2gus]

Error while creating work item. No valid build found in GUS!

[git2gus]

This issue has been linked to a new work item: W-17406558