Remove gogo from .proto files

While gogo isn't actually used, it is still referenced from .proto files
and its corresponding Go package is imported from the auto-generated
files.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>

runtime/linux/runctypes/runc.proto

@@ -2,8 +2,6 @@ syntax = "proto3";
 
 package containerd.linux.runc;
 
-import "gogoproto/gogo.proto";
-
 option go_package = "github.com/containerd/containerd/runtime/linux/runctypes;runctypes";
 
 message RuncOptions {

runtime/v1/shim/v1/shim.proto

@@ -20,7 +20,6 @@ package containerd.runtime.linux.shim.v1;
 
 import "google/protobuf/any.proto";
 import "google/protobuf/empty.proto";
-import "gogoproto/gogo.proto";
 import "google/protobuf/timestamp.proto";
 import "github.com/containerd/containerd/api/types/mount.proto";
 import "github.com/containerd/containerd/api/types/task/task.proto";

runtime/v2/runc/options/oci.proto

@@ -2,8 +2,6 @@ syntax = "proto3";
 
 package containerd.runc.v1;
 
-import "gogoproto/gogo.proto";
-
 option go_package = "github.com/containerd/containerd/runtime/v2/runc/options;options";
 
 message Options {