Skip benchmark workflow for bot review events

Bot reviews (AI code reviewers) were triggering the benchmark workflow,
and the concurrency group was cancelling the real benchmark run from
the pull_request event. Gate the workflow early by skipping when the
review author is a Bot account type.

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

Author: sbryngelson

.github/workflows/bench.yml

@@ -13,6 +13,9 @@ concurrency:
 jobs:
   file-changes:
     name: Detect File Changes
+    if: >
+      github.event_name != 'pull_request_review' ||
+      github.event.review.user.type != 'Bot'
     runs-on: 'ubuntu-latest'
     outputs:
       checkall: ${{ steps.changes.outputs.checkall }}