Hide out of stock variations from variable product page in WooCommerce

hide-out-of-stock-variations-in-woocommerce.php

add_filter( 'woocommerce_variation_is_visible', 'hide_out_of_stock_variations', 10, 4 );
function hide_out_of_stock_variations( $is_visible, $variation_id, $product_id, $variation ) {
    if ( ! $variation->is_in_stock() ) {
        $is_visible = false;
    }
    return $is_visible;
}