vendor: update buildkit to opentelemetry support

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

vendor/go.opentelemetry.io/otel/propagation/doc.go

@@ -0,0 +1,27 @@
+// 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.
+
+/*
+Package propagation contains OpenTelemetry context propagators.
+
+This package is currently in a Release Candidate phase. Backwards incompatible changes
+may be introduced prior to v1.0.0, but we believe the current API is ready to stabilize.
+
+OpenTelemetry propagators are used to extract and inject context data from and
+into messages exchanged by applications. The propagator supported by this
+package is the W3C Trace Context encoding
+(https://www.w3.org/TR/trace-context/), and W3C Baggage
+(https://w3c.github.io/baggage/).
+*/
+package propagation // import "go.opentelemetry.io/otel/propagation"