User creation failure in createUserAccountHandler is not retried

[JoseSzycho]

User creation failure in createUserAccountHandler is not retried

Description:
When the user creation fails in the createUserAccountHandler (see here the error is logged and an HTTP 500 is returned, but there is no retry logic implemented. This means that transient errors (such as temporary Kubernetes API issues) can cause permanent user creation failures.

Steps to reproduce:

1. Trigger a POST to /v1/actions/create-user-account with a valid payload.
2. Cause a transient failure in the Kubernetes API (e.g., network blip, API server restart).
3. Observe that the user creation is not retried and fails immediately.

Expected behavior:
The handler should implement a retry mechanism (with backoff and a reasonable limit) when creating the user resource, to improve reliability in the face of transient errors.