fix: skip rate validation for return DN Items with Moving Average valuation (backport #39242) (#39265)

* fix: skip rate validation for return `DN Items` with `Moving Average` valuation

(cherry picked from commit e0ad52b500)

# Conflicts:
#	erpnext/controllers/sales_and_purchase_return.py

* chore: `conflicts`

---------

Co-authored-by: s-aga-r <sagarsharma.s312@gmail.com>

erpnext/controllers/sales_and_purchase_return.py

@@ -8,7 +8,7 @@ from frappe.model.meta import get_field_precision
 from frappe.utils import flt, format_datetime, get_datetime
 
 import erpnext
-from erpnext.stock.utils import get_incoming_rate
+from erpnext.stock.utils import get_incoming_rate, get_valuation_method
 
 
 class StockOverReturnError(frappe.ValidationError):
@@ -116,7 +116,12 @@ def validate_returned_items(doc):
 				ref = valid_items.get(d.item_code, frappe._dict())
 				validate_quantity(doc, d, ref, valid_items, already_returned_items)
 
-				if ref.rate and doc.doctype in ("Delivery Note", "Sales Invoice") and flt(d.rate) > ref.rate:
+				if (
+					ref.rate
+					and flt(d.rate) > ref.rate
+					and doc.doctype in ("Delivery Note", "Sales Invoice")
+					and get_valuation_method(ref.item_code) != "Moving Average"
+				):
 					frappe.throw(
 						_("Row # {0}: Rate cannot be greater than the rate used in {1} {2}").format(
 							d.idx, doc.doctype, doc.return_against