Prevent 'BlockTemplatesController::add_archive_product_to_eligible_for_fallback_templates' to leak into classic themes

[Aljullu]

There is a method in BlockTemplatesController called add_archive_product_to_eligible_for_fallback_templates which seems to be leaking into classic themes. From my investigation, it doesn't have any impact in functionality, but we should make it so it only runs in block themes to avoid running unnecessary code and to prevent unexpected bugs.

The method can be found here:

woocommerce/plugins/woocommerce/src/Blocks/BlockTemplatesController.php

Lines 191 to 215 in de54195

	/**
	* Adds the `archive-product` template to the `taxonomy-product_cat`, `taxonomy-product_tag`, `taxonomy-attribute`
	* templates to be able to fall back to it.
	*
	* @param array $template_hierarchy A list of template candidates, in descending order of priority.
	*/
	public function add_archive_product_to_eligible_for_fallback_templates( $template_hierarchy ) {
	$template_slugs = array_map(
	'_strip_template_file_suffix',
	$template_hierarchy
	);
	$templates_eligible_for_fallback = array_filter(
	$template_slugs,
	function ( $template_slug ) {
	return BlockTemplateUtils::template_is_eligible_for_product_archive_fallback( $template_slug );
	}
	);
	if ( count( $templates_eligible_for_fallback ) > 0 ) {
	$template_hierarchy[] = ProductCatalogTemplate::SLUG;
	}
	return $template_hierarchy;
	}