test: make distinct() transaction test more durable

Author: vkarpov15

test/docs/transactions.test.js

@@ -344,7 +344,7 @@ describe('transactions', function() {
     const session = await db.startSession();
 
     session.startTransaction();
-    await Character.create([{ name: 'Will Riker', rank: 'Commander' }, { name: 'Jean-Luc Picard', rank: 'Captain' }], { session });
+    await Character.create([{ name: 'Will Riker', rank: 'Commander' }, { name: 'Jean-Luc Picard', rank: 'Captain' }], { session, ordered: true });
 
     let names = await Character.distinct('name', {}, { session });
     assert.deepStrictEqual(names.sort(), ['Jean-Luc Picard', 'Will Riker']);