Warning: Undefined variable $sale_percentage_val `

Under PHP 8.3, core/helpers/trip-pricing-categories.php throws an undefined property/variable warning because it lacks a null fallback check for $sale_percentage_val.

Error disappears when patching line 75 and 92 in core/helpers/trip-pricing-categories.php:

// $sale_percentage_val    = $result->sale_percentage_val;
$sale_percentage        = $result->sale_percentage_val ?? 0;

// $categories[ $index ]['sale_percentage_val']   = $sale_percentage_val;
$categories[ $index ]['sale_percentage_val']   = $sale_percentage_val ?? 0;