chore: remove promise creation

Author: nbbeeken

test/integration/client-side-operations-timeout/node_csot.test.ts

@@ -1023,8 +1023,7 @@ describe('CSOT driver tests', metadata, () => {
 
         beforeEach(async function () {
           cs = client.db('db').collection('coll').watch([], { timeoutMS: 120 });
-          const changePromise = once(cs, 'change');
-          void changePromise.then(undefined, () => null); // need to handled when this rejects with the timeout error
+          cs.once('change', () => null);
 
           await once(cs.cursor, 'init');