docs/data/reusables/webhooks/workflow_run_desc.md

This event occurs when a workflow run is requested or completed, and allows you to execute a workflow based on the finished result of another workflow. A workflow run is triggered regardless of the result of the previous workflow.

For example, if your pull_request workflow generates build artifacts, you can create a new workflow that uses workflow_run to analyze the results and add a comment to the original pull request.

The workflow started by the workflow_run event is able to access secrets and write tokens, even if the previous workflow was not. This is useful in cases where the previous workflow is intentionally not privileged, but you need to take a privileged action in a later workflow.