Increase server close timeout

Prior to Node.js 19.0.0, calling close while an idle client was connected to a
server would not actually close the server before the client disconnected. This
behavior was modified in Node.js 19.0.0:

nodejs/node#43522

This resulted in our mock server being closed before we expected and as a
result, some of the tests in `cluster.test.js` would fail. This is because the
1 second timeout is lower than the exponential backoff logic in the
`_autoRetry` function inside the `native_realm.js` file.

To get around this issue, the timeout have simply been incresed to 5 seconds
instead of 1. This is not pretty, but it gets the job done.

packages/kbn-es/src/integration_tests/__fixtures__/es_bin.js

@@ -87,11 +87,11 @@ const { ES_KEY_PATH, ES_CERT_PATH } = require('@kbn/dev-utils');
     }
   );
 
-  // setup server auto close after 1 second of silence
+  // setup server auto close after 5 second of silence
   let serverCloseTimer;
   const delayServerClose = () => {
     clearTimeout(serverCloseTimer);
-    serverCloseTimer = setTimeout(() => server.close(), 1000);
+    serverCloseTimer = setTimeout(() => server.close(), 5000);
   };
   server.on('request', delayServerClose);
   server.on('listening', delayServerClose);