workflow_run event with types:[completed] triggers before workflow actually completes

[amalc]

Bug Description

The workflow_run event with types: [completed] is incorrectly triggering BEFORE the referenced workflow actually completes, in addition to the correct trigger after completion.

Expected Behavior

According to GitHub Actions documentation, workflow_run with types: [completed] should only trigger AFTER the referenced workflow finishes running.

Actual Behavior

The workflow_run event triggers TWICE:

1. Once immediately after the referenced workflow starts (incorrect)
2. Once after the referenced workflow completes (correct)

Reproduction Steps

1. Create a workflow that triggers on workflow_run:

name: Deploy
on:
  workflow_run:
    workflows: ["CI/CD Pipeline"]
    types: [completed]
    branches: [develop]

2. Push code to trigger the CI/CD Pipeline workflow
3. Observe that the Deploy workflow triggers immediately (within seconds) while CI is still running
4. The Deploy workflow correctly skips because github.event.workflow_run.conclusion is not 'success'
5. Several minutes later, when CI completes, the Deploy workflow triggers again (correctly)

Evidence

Repository: amalc/launcher

Example sequence on 2025-09-10:

• CI/CD Pipeline started at 22:57:02 UTC (run ID: 17628907096)
• Deploy workflow triggered at 22:57:14 UTC (run ID: 17628910540) - INCORRECT, CI still running, correctly skipped
• CI/CD Pipeline completed successfully ~6 minutes later
• Deploy workflow triggered again at 23:03:57 UTC (run ID: 17629021343) - CORRECT, after CI completed

Impact

• Creates confusing "skipped" workflow runs in the Actions tab
• Wastes GitHub Actions minutes checking conditions unnecessarily
• Makes debugging deployment issues more difficult
• Could cause race conditions if the condition check is not properly implemented
• Clutters the Actions history with duplicate runs

Current Workaround

We check github.event.workflow_run.conclusion == 'success' which correctly skips premature triggers, but this shouldn't be necessary if the event only fired after completion as documented.

Environment

• Repository type: Public repository
• Workflow trigger: workflow_run with types: [completed]
• Affected branches: All branches specified in workflow_run trigger
• Runner: GitHub-hosted runners

Related Issues

This may be related to event queuing or race conditions in the GitHub Actions event dispatcher.

Please fix the workflow_run event to only trigger after the referenced workflow actually completes, matching the documented behavior.