Display product featured image in cart instead of variation thumbnail

variation-thumbnail.php

// Add this to your child theme's functions.php file
function wc_custom_cart_thumb( $thumb, $cart_item ) {
    return get_the_post_thumbnail( $cart_item['product_id'], 'shop_thumbnail' );
}
add_filter( 'woocommerce_cart_item_thumbnail', 'wc_custom_cart_thumb', 10, 2 );