vendor: update buildkit to master@cbfd4023383d

Signed-off-by: Justin Chadwell <me@jedevc.com>

vendor/github.com/moby/buildkit/solver/errdefs/jobs.go

@@ -0,0 +1,23 @@
+package errdefs
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/codes"
+)
+
+type UnknownJobError struct {
+	id string
+}
+
+func (e *UnknownJobError) Code() codes.Code {
+	return codes.NotFound
+}
+
+func (e *UnknownJobError) Error() string {
+	return fmt.Sprintf("no such job %s", e.id)
+}
+
+func NewUnknownJobError(id string) error {
+	return &UnknownJobError{id: id}
+}