Call a single function on two different methods with hooks

I’m not sure what you’re hoping for, but all you can really do is just move the code from one function into the other. global $post is also not doing anything, so removing that will save you a couple of lines:

/**
 * Register template
 */
public static function register_styles_templates() {
    add_filter('single_template', function($single_template) {
        if ($post->post_type == 'profile') {
            $single_template="/Users/smajlovs/Sites/newsacfoodies/htdocs/wp-content/mu-plugins/sacfoodies/profile-template.php";
        }

        return $single_template;
    });

    add_action('wp_enqueue_scripts', function() {
        if (is_page('foodies')) {
            wp_register_style('profile-style', content_url() . '/mu-plugins/sacfoodies/styles/profile-card.css');
            wp_enqueue_style('profile-style');
        }

        return;
    });
}