fix(esql): refresh keep_alive TTL on async query GET requests

[emreyalvac]

Summary

Fixes a bug in the ESQL async query API where updating the keep_alive value via a GET /_query/async/{id}?keep_alive=... request did not properly extend the lifetime of the async result, causing unexpected 404s after the original TTL expired.

Details

• The initial keep_alive duration specified in the POST request was honored, but follow-up GET requests with a new keep_alive value failed to refresh the TTL.
• This PR ensures that if a new keep_alive value is passed in the follow-up GET request, it will properly update the expiration time of the async result.

How to Reproduce (Before Fix)

1. Submit an async ESQL query with a short keep_alive, e.g. 15s.
2. Within the TTL window, send a GET /_query/async/{id}?keep_alive=60s
3. Wait >15s
4. Expect 404 (bug)

After Fix

• Async results will persist according to the most recent keep_alive value provided in the GET call.
• Prevents premature cleanup.

Related

Closes: #130619

[emreyalvac]

@kertal can you check?

[kertal]

thx @emreyalvac not sure who's the best to review this, since I just reported it , and it's something we need in Kibana. dear @elasticsearch-esql , can you help me (or know who can take care of it, thx) . If this is the solution I assume it needs at least one test to cover it