message: [CI] enable sccache in building bench
  Propagate existing CI optimization to bench build.
  Closes:
diff: @@ -435,16 +435,20 @@ jobs:
  RUST_BACKTRACE=1 $CARGO $CARGOFLAGS test \
  --features='vanilla' \
  --no-default-features
  - compile-benches:
  - executor: unittest-executor
  + build-benchmark:
  + executor: build-executor
  description: Compile (but don't run) the benchmarks, to insulate against bit rot
  steps:
  - build_setup
  + - restore_cargo_package_cache
  + - install_sccache
  + - restore_sccache
  - run:
  - name: Run bench --no-run
  + name: Build benchmark targets without running
  command: |
  RUST_BACKTRACE=1 $CARGO $CARGOFLAGS x bench \
  --no-run
  + - save_sccache
  run-flaky-unit-test:
  executor: test-executor
  description: Run a list of known flaky tests.
  @@ -749,7 +753,7 @@ workflows:
  - /^testflow[\d|.]+$/
  - /^premainnet-[\d|.]+$/
  - /^v[\d|.]+-release$/
  - - compile-benches:
  + - build-benchmark:
  requires:
  - prefetch-crates
  filters:
  