vendor: update buildkit to 539be170

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/google.golang.org/genproto/googleapis/api/httpbody/httpbody.pb.go

@@ -14,7 +14,7 @@
 
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.25.0-devel
+// 	protoc-gen-go v1.26.0
 // 	protoc        v3.12.2
 // source: google/api/httpbody.proto
 
@@ -24,7 +24,6 @@ import (
 	reflect "reflect"
 	sync "sync"
 
-	proto "github.com/golang/protobuf/proto"
 	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
 	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
 	anypb "google.golang.org/protobuf/types/known/anypb"
@@ -37,10 +36,6 @@ const (
 	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
 )
 
-// This is a compile-time assertion that a sufficiently up-to-date version
-// of the legacy proto package is being used.
-const _ = proto.ProtoPackageIsVersion4
-
 // Message that represents an arbitrary HTTP body. It should only be used for
 // payload formats that can't be represented as JSON, such as raw binary or
 // an HTML page.
@@ -61,12 +56,15 @@ const _ = proto.ProtoPackageIsVersion4
 //
 //       // The raw HTTP body is bound to this field.
 //       google.api.HttpBody http_body = 2;
+//
 //     }
 //
 //     service ResourceService {
-//       rpc GetResource(GetResourceRequest) returns (google.api.HttpBody);
-//       rpc UpdateResource(google.api.HttpBody) returns
-//       (google.protobuf.Empty);
+//       rpc GetResource(GetResourceRequest)
+//         returns (google.api.HttpBody);
+//       rpc UpdateResource(google.api.HttpBody)
+//         returns (google.protobuf.Empty);
+//
 //     }
 //
 // Example with streaming methods:
@@ -76,6 +74,7 @@ const _ = proto.ProtoPackageIsVersion4
 //         returns (stream google.api.HttpBody);
 //       rpc UpdateCalendar(stream google.api.HttpBody)
 //         returns (stream google.api.HttpBody);
+//
 //     }
 //
 // Use of this type only changes how the request and response bodies are