refactor: remove vendored Go repos, keep only .proto files

wfe-containerd-protos/proto/api/services/version/v1/version.proto

@@ -0,0 +1,33 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+syntax = "proto3";
+
+package containerd.services.version.v1;
+
+import "google/protobuf/empty.proto";
+
+// TODO(stevvooe): Should version service actually be versioned?
+option go_package = "github.com/containerd/containerd/api/services/version/v1;version";
+
+service Version {
+  rpc Version(google.protobuf.Empty) returns (VersionResponse);
+}
+
+message VersionResponse {
+  string version = 1;
+  string revision = 2;
+}