Summary

Infrastructure "Remove redundant pull_request trigger from IWYU Suggester workflow"

Purpose of change

The IWYU Suggester workflow was triggering on both pull_request and pull_request_target events, but the job's if condition only allowed pull_request_target runs through. Every pull_request event created a workflow run that immediately skipped, cluttering the Actions tab.

Also removed the draft PR gate so the suggester runs on drafts too, matching the main IWYU workflow.

Describe the solution

• Removed the pull_request trigger entirely since the job needs pull_request_target for write permissions anyway
• Simplified the concurrency group (no longer need to disambiguate by event name)
• Dropped the draft == false condition from the job

Describe alternatives you've considered

Could have added skip-duplicate-actions like matrix.yml uses, but the root cause was simpler - just a trigger that could never actually run.

Testing

N/A

Additional context

None