Elasticsearch Version
 main
 Installed Plugins
 No response
 Java Version
 bundled
 OS Version
 MacOS
 Problem Description
 When there are 2 or more concurrent _update requests issued, one of them may fail with ResourceAlreadyExistsException exception which is misleading.
 Steps to Reproduce
  - Spawn a number of _updaterequests at the same time
- Look at the results of these requests
- Observe ResourceAlreadyExistsExceptionbeing thrown in the case of conflict
Logs (if relevant)
 No response