Use the v2 protobuf module internally.

There's only one place where we use the protobuf APIs, so switch
to the v2 protobuf module.

This updates envoyproxy#524.

Signed-off-by: James Peach <jpeach@apache.org>

go.mod

@@ -19,9 +19,8 @@ require (
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/kr/pretty v0.3.0 // indirect
+	github.com/kr/pretty v0.3.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/rogpeppe/go-internal v1.9.0 // indirect
 	golang.org/x/net v0.17.0 // indirect
 	golang.org/x/sys v0.13.0 // indirect
 	golang.org/x/text v0.13.0 // indirect

go.sum

@@ -931,7 +931,6 @@ github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa02
 github.com/kr/fs v0.1.0/go.mod h1:FFnZGqtBN9Gxj7eW1uZ42v5BccTP0vu6NEaFoC2HwRg=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
-github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
 github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=

pkg/client/sotw/v3/client.go

@@ -21,11 +21,11 @@ import (
 	"io"
 	"sync"
 
-	"github.com/golang/protobuf/ptypes/any"
 	status "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	grpcStatus "google.golang.org/grpc/status"
+	"google.golang.org/protobuf/types/known/anypb"
 
 	core "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
 	discovery "github.com/envoyproxy/go-control-plane/envoy/service/discovery/v3"
@@ -54,7 +54,7 @@ type ADSClient interface {
 // For the time being it only contains the Resources from server. This can be extended with
 // other response details. For example some metadata from DiscoveryResponse.
 type Response struct {
-	Resources []*any.Any
+	Resources []*anypb.Any
 }
 
 type adsClient struct {