Skip benchmark workflow for bot review events (#1192)

* Skip benchmark workflow for bot review events

Bot reviews (AI code reviewers) trigger pull_request_review events that
start a new Benchmark workflow run. The concurrency group then cancels
the real benchmark run from the pull_request event, causing all
benchmark jobs to be cancelled on every PR with AI reviewers enabled.

Fix: skip the workflow early when the review author is a Bot account.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Use unique concurrency group for bot review runs

Job-level `if` doesn't prevent the workflow run from being created,
so the concurrency group still cancels in-progress runs. Fix by
giving bot review runs a unique concurrency group (appending run_id)
so they can't cancel real benchmark runs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix bot detection: use unique group for all review events

AI reviewer accounts (coderabbitai, copilot-pull-request-reviewer,
etc.) are Organization or User type, not Bot. Instead of trying to
detect bots, give all pull_request_review runs a unique concurrency
group so they never cancel pull_request benchmark runs. The self
job's if condition already gates for approved human reviews only.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: sbryngelson

.github/workflows/bench.yml

@@ -7,7 +7,7 @@ on:
   workflow_dispatch:
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
+  group: ${{ github.workflow }}-${{ github.ref }}${{ github.event_name == 'pull_request_review' && format('-review-{0}', github.run_id) || '' }}
   cancel-in-progress: true
 
 jobs: