Make quantity read only for the Empire theme

static-cart-extra.liquid

{% if has_items %}
<script>
  document.addEventListener("DOMContentLoaded", function(event) {
  {% for item in cart.items %}
    $('.cart-item--quantity:nth-child({{ forloop.index }})')
      .empty()
      .append({{ item.quantity }})
      .append('<input type="hidden" value="{{ item.quantity }}" name="updates[]" id="updates_{{ item.key }}">');
  {% endfor %}
  });
</script>
{% endif %}

Add this code to the end of the sections/static-cart.liquid file