[FIX] website_sale(_loyalty): fix disappearing code input

If incorrect code was applied, possibility of putting another
code was blocked.

task-3601317

closes odoo/odoo#144367

Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>

addons/website_sale/views/templates.xml

@@ -2450,7 +2450,7 @@
             <tr t-if="not hide_promotions">
                 <td colspan="3" class="text-end text-xl-end border-0 p-0">
                 <span>
-                    <t t-set="force_coupon" t-value="website_sale_order.pricelist_id.code or request.params.get('code_not_available')"/>
+                    <t t-set="force_coupon" t-value="website_sale_order.pricelist_id.code"/>
                     <div t-if="not force_coupon" class="coupon_form">
                         <t t-call="website_sale.coupon_form"/>
                     </div>

addons/website_sale_loyalty/views/website_sale_templates.xml

@@ -149,8 +149,7 @@
     </template>
 
     <template id="reduction_coupon_code" inherit_id="website_sale.reduction_code">
-        <xpath expr="//t[@t-set='force_coupon']" position="replace">
-            <t t-set='force_coupon' t-value="website_sale_order.pricelist_id.code or request.params.get('code_not_available') or website_sale_order.get_promo_code_error(delete=False)"/>
+        <xpath expr="//t[@t-set='force_coupon']" position="after">
             <t t-set="_placeholder" t-value="'Discount code or gift card'"/>
         </xpath>
     </template>