fix: pass stock_qty to get_pricing_rule_for_item

get_pricing_rule_for_item uses the "stock_qty" and "qty" arguments to filter pricing rules.
Not passing stock_qty prevents for example the shopping cart from filtering pricing rules appropriately based on Quantity.
diff --git a/erpnext/utilities/product.py b/erpnext/utilities/product.py
index c23c1f7..66d6cd3 100644
--- a/erpnext/utilities/product.py
+++ b/erpnext/utilities/product.py
@@ -82,6 +82,7 @@
 			pricing_rule = get_pricing_rule_for_item(frappe._dict({
 				"item_code": item_code,
 				"qty": qty,
+				"stock_qty": qty,
 				"transaction_type": "selling",
 				"price_list": price_list,
 				"customer_group": customer_group,