cmd/emv/internal/t8ntool: fix shadowing of excessBlobGas (ethereum#29263)

fix(t8n): unexpected `excessBlobGas` shadowed

Author: dyxushuai

cmd/evm/internal/t8ntool/execution.go

@@ -169,7 +169,7 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 	// Calculate the BlobBaseFee
 	var excessBlobGas uint64
 	if pre.Env.ExcessBlobGas != nil {
-		excessBlobGas := *pre.Env.ExcessBlobGas
+		excessBlobGas = *pre.Env.ExcessBlobGas
 		vmContext.BlobBaseFee = eip4844.CalcBlobFee(excessBlobGas)
 	} else {
 		// If it is not explicitly defined, but we have the parent values, we try