feat: optimize evm.charge_gas

[ClementWalter]

Feature Request

Based on the analysis from #1256 , I think (to be tested) that charge_gas could be cheaper by doing

func charge_gas{range_check_ptr}(self: model.EVM*, amount: felt) -> model.EVM* {
    let gas_left = self.gas_left - amount;
    let enough_gas = is_nn(gas_left);

    if (enough_gas != 0) {
        return new model.EVM(
            message=self.message,
            return_data_len=self.return_data_len,
            return_data=self.return_data,
            program_counter=self.program_counter,
            stopped=self.stopped,
            gas_left=gas_left,
            gas_refund=self.gas_refund,
            reverted=self.reverted,
        );
    }
    let (revert_reason_len, revert_reason) = Errors.outOfGas(self.gas_left, amount);
    return new model.EVM(
        message=self.message,
        return_data_len=revert_reason_len,
        return_data=revert_reason,
        program_counter=self.program_counter,
        stopped=TRUE,
        gas_left=0,
        gas_refund=self.gas_refund,
        reverted=Errors.EXCEPTIONAL_HALT,
    );
}

The is_nn should also be inline to avoid the extra call steps