ttrpc: cannot marshal unknown type: *proto.CreateVMRequest when using socket

Hi everyone,
I'm trying to build a custom utility to start VMs and containers using firecracker-containerd and your SDK.

As a first test I tried to replicate one of the tests in your code to see if I could properly connect to my firecracker-containerd socket and start a VM, however I'm getting the error that you can see in the title.

My guess is that there is some kind of version mismatch between the proto version that is published on this repo and the actual one used by my socket, even if I'm on latest version for both (by latest I mean that I cloned the repo and build from source).

Here are some details on my environment and code:
```
$ firecracker-containerd --version
containerd github.com/containerd/containerd 1.6.20+unknown 3fae0bdd0f592581a2e0519fd6c307b8549569f8
```

_go imports_
```
require (
github.com/containerd/containerd v1.6.23
github.com/firecracker-microvm/firecracker-containerd v0.0.0-20230901203207-fc5e81ef584b
github.com/gogo/protobuf v1.3.2
)
```

_go code_
```
fmt.Println("Creating VM")
_, err = fcClient.CreateVM(ctx, &proto.CreateVMRequest{
VMID: vmID,
NetworkInterfaces: []*proto.FirecrackerNetworkInterface{{
AllowMMDS: true,
// This assumes the demo CNI network has been installed
CNIConfig: &proto.CNIConfiguration{
NetworkName: "fcnet",
InterfaceName: "veth0",
},
}},
})
```

Any idea on what could be going wrong?