Hide shipping methods based on products categories in Woocommerce

I have revisited your code and here is correct way to make it work for variable products too:

add_filter( 'woocommerce_package_rates', 'product_category_hide_shipping_methods', 90, 2 );function product_category_hide_shipping_methods( $rates, $package ){    // HERE set your product categories in the array (IDs, slugs or names)    $categories = array( 'clothing');    $found = false;    // Loop through each cart item Checking for the defined product categories    foreach( $package['contents'] as $cart_item ) {        if ( has_term( $categories, 'product_cat', $cart_item['product_id'] ) ){            $found = true;            break;        }    }    $rates_arr = array();    if ( $found ) {        foreach($rates as $rate_id => $rate) {             if ('local_pickup' === $rate->method_id) {                $rates_arr[ $rate_id ] = $rate;            }        }    }    return !empty( $rates_arr ) ? $rates_arr : $rates;}

Code goes in function.php file of your active child theme (or active theme). Tested and works.

You should need to refresh the shipping caches:
1) First this code is already saved on your function.php file.
2) In Shipping settings, enter in a Shipping Zone and disable a Shipping Method and "save". Then re-enable that Shipping Method and "save". You are done.