This is the result of spike done in https://gitlab.com/gitlab-org/gitlab/-/issues/365363. We want to allow users to see real-time updates on reviewers. It should be triggered when the following happens: 1. A new reviewer is added. 2. A reviewer is removed. 3. Reviewer state changes. <!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION --> *This page may contain information related to upcoming products, features and functionality. It is important to note that the information presented is for informational purposes only, so please do not rely on the information for purchasing or planning purposes. Just like with all projects, the items mentioned on the page are subject to change or delay, and the development, release, and timing of any products, features, or functionality remain at the sole discretion of GitLab Inc.* <!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION -->