Avoid unrelated items from affecting finishing onboarding

What does this MR do and why?

Avoid unrelated items from affecting finishing onboarding

• We are encountering issues removing users from onboarding that seem unrelated to our core concern of finishing onboarding. See https://gitlab.com/gitlab-org/gitlab/-/issues/520090#note_2398552531
• We'll try and then log issues with a limit to try and get to the root cause, but then skip validations here so that the user's issue is resolved.
• See https://gitlab.com/gitlab-org/gitlab/-/issues/520090

Changelog: fixed EE: true

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #520090

Related to #526038 (closed)