function texora_premium_palette_assets() {
    $file = get_template_directory() . '/assets/css/premium-palette.css';
    wp_enqueue_style('texora-premium-palette', get_template_directory_uri() . '/assets/css/premium-palette.css', array(), file_exists($file) ? filemtime($file) : '3.3.0');
}
add_action('wp_enqueue_scripts', 'texora_premium_palette_assets', 999);
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://test.aaralabs.com/wp-sitemap-index.xsl" ?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><sitemap><loc>https://test.aaralabs.com/wp-sitemap-posts-post-1.xml</loc></sitemap><sitemap><loc>https://test.aaralabs.com/wp-sitemap-posts-page-1.xml</loc></sitemap><sitemap><loc>https://test.aaralabs.com/wp-sitemap-taxonomies-category-1.xml</loc></sitemap><sitemap><loc>https://test.aaralabs.com/wp-sitemap-users-1.xml</loc></sitemap></sitemapindex>