Add a Slack status notification to the internal_release_finalize:notify_releases job

Problem Statement

The internal_release_finalize:notify_releases job notifies the release managers when internal packages are built and available.

However, the job misses the final Slack message notifying the job status.

Exit Criteria

This issue is to add a Slack notification when the job finishes, indicating the status (success or failure) and the job name. Example of other internal release jobs: