Require Irish or any postcode on billing form

Hi,
I’m having trouble making the Irish postcode field to be required. I tried bunch of different snippets to include in functions.php file but none of them work. I finally found a line in woocommerce include/class-wc-countries.php file that listed Irish postcode:

‘IE’ => array(
‘postcode’ => array(
‘required’ => false,
‘label’ => __( ‘Eircode’, ‘woocommerce’ ),
…

When I’ve changed ‘false’ to ‘true’ it finally worked but I know that’s the worst way to do it – changing core woocommerce code.

Is there a good working snippet that will override this so when I update the plugin the change will stay?

I’m running the latest woo 3.7.0