godeps: Upgrade kubernetes client libraries 1.20.4→1.21.9 [ci-skip]

Besides just a search/replace for the version number, this also involved:

 - rebasing github.com/emissary-ingress/code-generator
 - adding `option go_package` to our .proto files, since the newer
   protoc-gen-go that will get pulled in is pickier about them (thanks
   @aidanhahn for this one)

I went to 1.21 instead of 1.22 or 1.23 because
k8s.ip/kube-openapi@4e36c7e0cbd6d08c871dc44f2d2be29108874175 (which is
in the 1.22 branch) changes the meaning of "spec" in

    type OpenAPIDefinition struct {
        Schema       spec.Schema
        Dependencies []string
    }

from "github.com/go-openapi/spec" to
"k8s.io/kube-openapi/pkg/validation/spec", which breaks lots of
external users, such as the Argo libraries that the agent uses.

So stick with 1.21.x for now.

Signed-off-by: Aidan Hahn <[email protected]>
Signed-off-by: Luke Shumaker <[email protected]>

api/agent/director.proto

@@ -10,6 +10,8 @@ import "google/protobuf/timestamp.proto";
 
 package agent;
 
+option go_package = "./agent";
+
 service Director {
   // Report a consistent Snapshot of information to the CEPC.  This
   // method is deprecated, you should call ReportStream instead.

api/kat/echo.proto

@@ -2,6 +2,8 @@ syntax = "proto3";
 
 package echo;
 
+option go_package = "./kat";
+
 service EchoService {
     rpc Echo(EchoRequest) returns (EchoResponse) {}
 }

go.mod

@@ -73,7 +73,7 @@ exclude (
 // We've got some bug-fixes that we need for conversion-gen and
 // controller-gen.
 replace (
-	k8s.io/code-generator v0.20.4 => github.com/emissary-ingress/code-generator v0.20.5-rc.0.0.20220120231034-6c7797b9220f
+	k8s.io/code-generator v0.21.9 => github.com/emissary-ingress/code-generator 4708b255a33a7669887e40a993c65f5b8fa56ed7
 	sigs.k8s.io/controller-tools v0.5.0 => github.com/emissary-ingress/controller-tools v0.5.1-0.20220120234851-b97c2515f1c2
 )
 
@@ -107,17 +107,17 @@ require (
 	google.golang.org/grpc v1.34.0
 	google.golang.org/protobuf v1.25.0
 	gopkg.in/yaml.v2 v2.4.0
-	k8s.io/api v0.20.4
-	k8s.io/apiextensions-apiserver v0.20.4
-	k8s.io/apimachinery v0.20.4
-	k8s.io/cli-runtime v0.20.4
-	k8s.io/client-go v0.20.4
-	k8s.io/code-generator v0.20.4
+	k8s.io/api v0.21.9
+	k8s.io/apiextensions-apiserver v0.21.9
+	k8s.io/apimachinery v0.21.9
+	k8s.io/cli-runtime v0.21.9
+	k8s.io/client-go v0.21.9
+	k8s.io/code-generator v0.21.9
 	k8s.io/klog/v2 v2.10.0
 	k8s.io/kube-openapi v0.0.0-20210304212320-e467f52fd9db
-	k8s.io/kubectl v0.20.4
-	k8s.io/kubernetes v1.20.4
-	k8s.io/metrics v0.20.4
+	k8s.io/kubectl v0.21.9
+	k8s.io/kubernetes v1.21.9
+	k8s.io/metrics v0.21.9
 	sigs.k8s.io/controller-runtime v0.8.0
 	sigs.k8s.io/controller-tools v0.5.0
 	sigs.k8s.io/gateway-api v0.2.0
@@ -197,8 +197,8 @@ require (
 	google.golang.org/appengine v1.6.6 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
-	k8s.io/apiserver v0.20.4 // indirect
-	k8s.io/component-base v0.20.4 // indirect
+	k8s.io/apiserver v0.21.9 // indirect
+	k8s.io/component-base v0.21.9 // indirect
 	k8s.io/gengo v0.0.0-20201214224949-b6c5ce23f027 // indirect
 	k8s.io/utils v0.0.0-20201110183641-67b214c5f920 // indirect
 	sigs.k8s.io/kustomize v2.0.3+incompatible // indirect