dont' recover signer in a hot loop (#212)

## 📝 Summary

This is pretty serious regression that I've missed while reviewing
external PR on one of the reth upgrades.

We need to be careful to not allow something like that slip in the
future.

## 💡 Motivation and Context

calling recover_signer verifies transaction signature every time we try
to executing something in the vm.

---

## ✅ I have completed the following steps:

* [ ] Run `make lint`
* [ ] Run `make test`
* [ ] Added tests (if applicable)

Author: dvush

crates/rbuilder/src/building/order_commit.rs

@@ -420,8 +420,8 @@ impl<'a, 'b, Tracer: SimulationTracer> PartialBlockFork<'a, 'b, Tracer> {
         }
 
         let mut tx_env = TxEnv::default();
-        let tx_signed = tx_with_blobs.internal_tx_unsecure().clone().into_signed();
-        tx_signed.fill_tx_env(&mut tx_env, tx_signed.recover_signer().unwrap());
+        let tx_signed = tx_with_blobs.internal_tx_unsecure();
+        tx_signed.fill_tx_env(&mut tx_env, tx_signed.signer());
 
         let env = Env {
             cfg: ctx.initialized_cfg.cfg_env.clone(),