How can I get the custom post type assigned to a current custom taxonomy for query?

Question

I will query all posts of a custom post type if the visitor is in the assigned custom taxonomy. I can use an array of all my custom post types in the argument list, but I want to do it dynamicly with the informations of the category the visitior is in. Is there a way to get the custom post type name from the current taxonomy?

$paged = ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : 1;
if ( ! $paged ) {
    $paged = ( get_query_var( 'page' ) ) ? get_query_var( 'page' ) : 1;
}

$posts_per_page = get_option( 'posts_per_page' );

// Get the queried object and sanitize it
$current_page = sanitize_post( $GLOBALS['wp_the_query']->get_queried_object() );
// Get the slug
$slug_taxonomy  = @$current_page->taxonomy;

// Check if I'm in a category
if ( isset( $slug_taxonomy ) && ! is_null( $slug_taxonomy ) && ! empty( $slug_taxonomy ) ) {
    $query = new WP_Query( array(
            'posts_per_page' => $posts_per_page,
            'post_type'      => 'i_dont_know',   // How can I get the custom post type?
            'paged'          => $paged,
            'post_status'    => 'publish',
            'orderby'        => 'title',
            'order'          => 'ASC',
            'tax_query'      => array(
                array(
                    'taxonomy' => $current_page->taxonomy,
                    'field'    => 'term_id',
                    'terms'    => $current_page->term_id,
                )
            )
        )
    );
}

Answer 1

You can use 'post_type' => 'any' if you are not sure of the post types resulting from other query arguments.

According to documentation that is what happens by default when you use tax_query:

post_type (string / array) - use post types. Retrieves posts by Post Types, default value is 'post'. If 'tax_query' is set for a query, the default value becomes 'any'

WP_Query / Type parameters

Outside of WP_Query context you would probably need to get such information from global $wp_taxonomies array, which track taxonomies and post types they apply to.