feat: disable bench ci steps on scroll branch

[Thegaram]

This action is failing with

    Finished `profiling` profile [optimized + debuginfo] target(s) in 1m 58s
     Running benches/iai.rs (target/profiling/deps/iai-068d5ba708ef06ee)
iai_callgrind_runner: Error: Failed to decode configuration
error: bench failed, to rerun pass `-p reth-db --bench iai`

Caused by:
  process didn't exit successfully: `/home/runner/work/reth/reth/target/profiling/deps/iai-068d5ba708ef06ee --save-baseline=base --bench` (exit status: 1)
Error: Process completed with exit code 1.

in the "save baseline" step.

I traced this error back to here and here, but I have not been able to fix it yet. Since we probably won't change this db serialization par, it is fine to disable this action.