Capture approval rule changes in Audit events when the policy configuration last updated user is not available in GitLab

Why are we doing this work

When the Policy created user is not available in GitLab. We do not create audit event for approval rule changes as we observed it to be causing this error. So we are skipping audit event for this scenario and the same can be revisited when the security bot user is available which can be used as a fallback user and then perform audit.

Issue created based on context from related discussion #402173 (comment 1350359197):

Once Use bot users to trigger scan execution policie... (#394958 - closed) is complete, we might solve all those cases. So, until then I'd suggest to handle the exceptions gracefully in those places and update documentation to mention that the scheduled scan execution policy

Relevant links

• AuditEvents::BuildService::MissingAttributeErro... (#402173 - closed)
• Use bot users to trigger scan execution policie... (#394958 - closed)

Non-functional requirements

• Documentation:
• Feature flag:
• Performance:
• Testing:

Implementation plan

Verification steps