func (sys *IAMSys) updateGroupMembershipsForLDAP(ctx context.Context) {
	// 1. Collect all LDAP users with active creds.
	allCreds := sys.store.GetSTSAndServiceAccounts()
	// List of unique LDAP (parent) user DNs that have active creds
	var parentUserActualDNList []string
	// Map of LDAP user (internal representation) to list of active credential objects