TEMP: fire aiur-bench on sb/aiur-ci-bench to test pre-merge

Revert before merging. Scopes the push trigger to this branch so the
benchmark workflow can be exercised end-to-end; Bencher data lands under
the `sb/aiur-ci-bench` branch, isolated from `main`'s plots.

Author: samuelburnham

.github/workflows/aiur-bench.yml

@@ -12,7 +12,7 @@ name: Aiur benchmarks
 
 on:
   push:
-    branches: main
+    branches: sb/aiur-ci-bench
   workflow_dispatch:
 
 permissions: