Elasticsearch Write Index Issue: "no write index is defined for alias [prefix-variants]"

[Guts996]

Describe the bug

Issue Description

I’m encountering an issue with Elasticsearch integration in my Vendure multivendor app. When trying to update or delete documents in the prefix-variants index, I receive the following error:

To Reproduce
Steps to reproduce the behavior:

1. Set up Vendure with Elasticsearch plugin.
2. Trigger a product update or reindex operation.
3. See error log:

[worker] {
"type": "illegal_argument_exception",
"reason": "no write index is defined for alias [izar-variants]. The write index may be explicitly disabled using is_write_index=false or the alias points to multiple indices without one being designated as a write index"
}

Environment :

• @vendure/core version: 3.1.1
• Nodejs version : v23.6.0
• Database postgres
• Elastic Search : elasticsearch:7.13.0

Additional context
I'm running elastic search on docker container, correctly setup
I'm using the multivendor plugin