Move event streaming in to after commit queue

What does this MR do and why?

• Moves the call to stream audit events in to the after commit queue to fix errors where the sidekiq jobs were being scheduled within a transaction which is not allowed.
• Errors have caused groupcompliance to miss their error budgets significantly.
• Errors: (internal link): https://sentry.gitlab.net/gitlab/gitlabcom/?query=is%3Aunresolved+AuditEventStreamingWorker.perform_async

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #347108 (closed)