Rounding Taxes

Our WooCommerce shop is using the currency CHF. To comply with the shop system for our local orders we want it to round the total and the taxes to 0.05.

I already managed to round the total like that in the functions.php:

add_filter( 'woocommerce_calculated_total', 'round_price_product', 10, 1);
function round_price_product( $price ){
return round(($price + 0.000001) * 20) / 20;
}

Unfourtunately I have no Idea how to round the taxes. (in the example 0.46 to 0.45).
Example

Does someone know what I need to add in the functions.php so it will be rounded too?