Add audit event for group member removal because of inactive SCIM identity

Proposal

Add audit event when a user is removed from a group during SAML authentication when their SCIM identity is inactive.

FF skip_saml_identity_destroy_during_scim_deprovision was enabled via #410234 (closed), now users who do not have an active SCIM identity are added and instantly removed from the group. However, no audit event of the removal exists.

Related MRs

• !120049 (merged)
• !128588 (merged)

Steps to reproduce

• Enable Group SAML and SCIM
• Add user to SCIM application
• Remove user from SCIM application
  • Audit event for group removal does occur here
• Affected user authenticates via SAML
  • Audit events show the authentication was successful
  • Audit events show that the user was added with the default role
• User is immediately removed from the group
• User receives a 404

Environment

GitLab.com, GitLab Enterprise Edition 16.4.0-pre 237ab0bc