test(ci): trigger bench-main + zkVM-build on branch pushes (TEMPORARY)

Push-to-branch triggers so the full bench (incl. the zkvm-execute job
with the new --consts full-closure hosts, execute-peak-rss, and the RAM
watchdog) and the zkVM build gate run pre-merge.

DROP THIS COMMIT BEFORE MERGE — it is the sole carrier of both
temporary triggers. Notes for the test runs: bencher uploads land under
branch `sb/ci-benchmarks` (isolated from main's baselines; the
threshold window query finds zero reports there, so thresholds are
omitted on first upload), and the bench-bins-/bench-ixe- caches this
run saves are keyed by branch SHA, harmless.

Author: samuelburnham

.github/workflows/bench-main.yml

@@ -17,7 +17,7 @@ name: Benchmark main
 
 on:
   push:
-    branches: main
+    branches: [main, sb/ci-benchmarks]   # TEMPORARY: test on this branch
   workflow_dispatch:
 
 permissions:

.github/workflows/riscv-bench.yml

@@ -11,7 +11,7 @@ name: zkVM host build
 # + const-tree regeneration per run).
 on:
   push:
-    branches: main
+    branches: [main, sb/ci-benchmarks]   # TEMPORARY: test on this branch
   workflow_dispatch:
 
 permissions: