fix: test for raising MR-SE mismatch error

- Make test add mismatched item code instead of warehouse, since warehouse can be different.
diff --git a/erpnext/stock/doctype/material_request/test_material_request.py b/erpnext/stock/doctype/material_request/test_material_request.py
index 0a29fa0..72a3a5e 100644
--- a/erpnext/stock/doctype/material_request/test_material_request.py
+++ b/erpnext/stock/doctype/material_request/test_material_request.py
@@ -424,6 +424,7 @@
 			"basic_rate": 1.0
 		})
 		se_doc.get("items")[1].update({
+			"item_code": "_Test Item Home Desktop 100",
 			"qty": 3.0,
 			"transfer_qty": 3.0,
 			"s_warehouse": "_Test Warehouse 1 - _TC",
@@ -534,7 +535,7 @@
 
 		mr = make_material_request(item_code='_Test FG Item', material_request_type='Manufacture',
 			uom="_Test UOM 1", conversion_factor=12)
-		
+
 		requested_qty = self._get_requested_qty('_Test FG Item', '_Test Warehouse - _TC')
 
 		self.assertEqual(requested_qty, existing_requested_qty + 120)