Schema validation error during onboarding

Summary

Users have observed a schema validation error during the onboarding process after registering a new account.

Zendesk tickets (internal):

• https://gitlab.zendesk.com/agent/tickets/515870
• https://gitlab.zendesk.com/agent/tickets/515917
• https://gitlab.zendesk.com/agent/tickets/515926

Internal slack discussion: https://gitlab.slack.com/archives/CQBSKU99C/p1711732221786829
Likely related MR: Add registration_type storing to the onboarding... (!146548 - merged)

Steps to reproduce

I was unable to reproduce

What is the current bug behavior?

User receives the following:

1 error prohibited this user from being saved:

User detail onboarding status must be a valid json schema

What is the expected correct behavior?

User should not receive the error and be allowed to proceed in the onboarding process.

Relevant logs and/or screenshots

• Kibana: https://log.gprd.gitlab.net/app/r/s/se5Vh
• Sentry: https://new-sentry.gitlab.net/organizations/gitlab/issues/742096
• 

Analysis

#452530 (comment 1838422656)

Follow-up Actions for this issue to address

• Reproduce this issue locally by registering a user on the new code and then stopping GDK and submitting the welcome page on the old code.
  • see #452530 (comment 1846995313)
• Consider adding logging of errors with detail around onboarding status values when the user is saved on the welcome page here
  • #452530 (comment 1846994852)
• Document how to ensure we don't get in this problem again when adding fields to the json schema for onboarding status