vendor: update buildkit to v0.19.0-rc1

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

vendor/k8s.io/klog/v2/safeptr.go

@@ -0,0 +1,34 @@
+//go:build go1.18
+// +build go1.18
+
+/*
+Copyright 2023 The Kubernetes 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 klog
+
+// SafePtr is a function that takes a pointer of any type (T) as an argument.
+// If the provided pointer is not nil, it returns the same pointer. If it is nil, it returns nil instead.
+//
+// This function is particularly useful to prevent nil pointer dereferencing when:
+//
+//   - The type implements interfaces that are called by the logger, such as `fmt.Stringer`.
+//   - And these interface implementations do not perform nil checks themselves.
+func SafePtr[T any](p *T) any {
+	if p == nil {
+		return nil
+	}
+	return p
+}