fix(e-commerce): shopping cart total quantity (#29076)

* fix: shopping cart total quantity

* fix: linter error
diff --git a/erpnext/e_commerce/shopping_cart/cart.py b/erpnext/e_commerce/shopping_cart/cart.py
index a8c9b8e..ee47e64 100644
--- a/erpnext/e_commerce/shopping_cart/cart.py
+++ b/erpnext/e_commerce/shopping_cart/cart.py
@@ -23,7 +23,7 @@
 	if cint(frappe.db.get_singles_value("E Commerce Settings", "enabled")):
 		if not quotation:
 			quotation = _get_cart_quotation()
-		cart_count = cstr(len(quotation.get("items")))
+		cart_count = cstr(cint(quotation.get("total_qty")))
 
 		if hasattr(frappe.local, "cookie_manager"):
 			frappe.local.cookie_manager.set_cookie("cart_count", cart_count)