perf(minor): remove unnecessary comprehensions (#25645)

diff --git a/erpnext/controllers/tests/test_mapper.py b/erpnext/controllers/tests/test_mapper.py
index 66459fd..7a4b2d3 100644
--- a/erpnext/controllers/tests/test_mapper.py
+++ b/erpnext/controllers/tests/test_mapper.py
@@ -26,8 +26,8 @@
 
 		# Assert that all inserted items are present in updated sales order
 		src_items = item_list_1 + item_list_2 + item_list_3
-		self.assertEqual(set([d for d in src_items]),
-			set([d.item_code for d in updated_so.items]))
+		self.assertEqual(set(d for d in src_items),
+			set(d.item_code for d in updated_so.items))
 
 
 	def make_quotation(self, item_list, customer):