vendor: update buildkit to v0.18.0-rc1

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

vendor/go.opentelemetry.io/otel/trace/trace.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry 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.
+// SPDX-License-Identifier: Apache-2.0
 
 package trace // import "go.opentelemetry.io/otel/trace"
 
@@ -361,6 +350,12 @@ type Span interface {
 	// AddEvent adds an event with the provided name and options.
 	AddEvent(name string, options ...EventOption)
 
+	// AddLink adds a link.
+	// Adding links at span creation using WithLinks is preferred to calling AddLink
+	// later, for contexts that are available during span creation, because head
+	// sampling decisions can only consider information present during span creation.
+	AddLink(link Link)
+
 	// IsRecording returns the recording state of the Span. It will return
 	// true if the Span is active and events can be recorded.
 	IsRecording() bool