Update protobuf,grpc,etcd dependencies

1. Updated etcd/protobuf/grpc dependencies:

echo "
hack/pin-dependency.sh github.com/golang/protobuf latest
hack/pin-dependency.sh google.golang.org/protobuf latest
hack/pin-dependency.sh go.etcd.io/etcd/api/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/client/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/client/pkg/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/pkg/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/server/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/tests/v3 v3.5.0-rc.0
hack/pin-dependency.sh google.golang.org/grpc latest
" | bash

2. Linted transitive dependencies until versions are clean:

hack/lint-dependencies.sh  | grep "  hack/pin-dependency.sh" | bash

3. Linted dependencies until dropped versions are clean:

hack/lint-dependencies.sh  | grep "dropreplace" | bash

4. Updated vendor and internal modules:

hack/update-vendor.sh
hack/update-internal-modules.sh

Repeated steps 2-4 until clean

vendor/github.com/golang/protobuf/proto/registry.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"sync"
 
+	"google.golang.org/protobuf/reflect/protodesc"
 	"google.golang.org/protobuf/reflect/protoreflect"
 	"google.golang.org/protobuf/reflect/protoregistry"
 	"google.golang.org/protobuf/runtime/protoimpl"
@@ -62,14 +63,7 @@ func FileDescriptor(s filePath) fileDescGZIP {
 	// Find the descriptor in the v2 registry.
 	var b []byte
 	if fd, _ := protoregistry.GlobalFiles.FindFileByPath(s); fd != nil {
-		if fd, ok := fd.(interface{ ProtoLegacyRawDesc() []byte }); ok {
-			b = fd.ProtoLegacyRawDesc()
-		} else {
-			// TODO: Use protodesc.ToFileDescriptorProto to construct
-			// a descriptorpb.FileDescriptorProto and marshal it.
-			// However, doing so causes the proto package to have a dependency
-			// on descriptorpb, leading to cyclic dependency issues.
-		}
+		b, _ = Marshal(protodesc.ToFileDescriptorProto(fd))
 	}
 
 	// Locally cache the raw descriptor form for the file.