txn test fix 3

Author: aditi-khare-mongoDB

test/integration/node-specific/client_close.test.ts

@@ -470,7 +470,7 @@ describe('MongoClient.close() Integration', () => {
       client = this.configuration.newClient();
       utilClient = this.configuration.newClient();
       await client.connect();
-      const collection = client.db('db').collection('collection');
+      const collection = await client.db('db').collection('collection');
       session = client.startSession({ explicit: false });
       session.startTransaction();
       await collection.insertOne({ x: 1 }, { session });
@@ -532,7 +532,7 @@ describe('MongoClient.close() Integration', () => {
       client = this.configuration.newClient();
       utilClient = this.configuration.newClient();
       await client.connect();
-      const collection = client.db('db').collection('collection');
+      const collection = await client.db('db').collection('collection');
       session = client.startSession();
       session.startTransaction();
       await collection.insertOne({ x: 1 }, { session });