test: Make Variant if absent in test_variant_work_order, keep test atomic

erpnext/stock/doctype/stock_entry/test_stock_entry.py

@@ -691,6 +691,8 @@ class TestStockEntry(ERPNextTestCase):
 		bom_no = frappe.db.get_value("BOM", {"item": "_Test Variant Item",
 			"is_default": 1, "docstatus": 1})
 
+		make_item_variant() # make variant of _Test Variant Item if absent
+
 		work_order = frappe.new_doc("Work Order")
 		work_order.update({
 			"company": "_Test Company",