Fees not shown in Cart & Checkout blocks for orders that don't need shipping

[Aljullu]

Describe the bug

Fees amount is not displayed in Cart & Checkout blocks sidebar if the order doesn't need shipping.

Discovered while working on #2712.

To reproduce

Add this code snippet to any PHP file, for example, woocommerce-gutenberg-products-block.php:

add_action( 'woocommerce_cart_calculate_fees', 'add_fee', 10 );
function add_fee( $cart ) {
	$cart->add_fee( __( 'Fee', 'woo-gutenberg-products-block' ), 100, true );
}

1. Add a product that doesn't need shipping (ie: Album) and a product that needs shipping (ie: Cap) to your cart.
2. Go to the Cart or Checkout pages (using blocks).
3. Notice the Fees amount appears as expected:
   
4. Remove the product that needs shipping from the Cart and notice how the Fees amount disappears: