Show All products on Shop page.php

// Woocommerce Show All products on Shop page

/**
 * Change number of products that are displayed per page (shop page)
 */
add_filter( 'loop_shop_per_page', 'new_loop_shop_per_page', 20 );

function new_loop_shop_per_page( $cols ) {
  // $cols contains the current number of products per page based on the value stored on Options -> Reading
  // Return the number of products you wanna show per page.
  $cols = -1;
  return $cols;
}

// Woocommerce Show 4 Column in products

add_filter( 'loop_shop_columns', 'new_cl_loop_columns_per_page', 20 );

/**
 * How many columns per page
 * @since 1.0.0
 */
function new_cl_loop_columns_per_page( $cols ) {
    // Return the number of columns you want show per page.
    $cols = 4;
    return $cols;
}