vendor: update buildkit to v0.14.0-rc1

Update buildkit dependency to v0.14.0-rc1. Update the tracing
infrastructure to use the new detect API which updates how the delegated
exporter is configured.

Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>

vendor/github.com/moby/buildkit/cmd/buildkitd/config/gcpolicy.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/docker/go-units"
+	"github.com/moby/buildkit/util/bklog"
 	"github.com/pkg/errors"
 )
 
@@ -104,3 +105,25 @@ func stripQuotes(s string) string {
 	}
 	return s
 }
+
+func DetectDefaultGCCap() DiskSpace {
+	return DiskSpace{Percentage: DiskSpacePercentage}
+}
+
+func (d DiskSpace) AsBytes(root string) int64 {
+	if d.Bytes != 0 {
+		return d.Bytes
+	}
+	if d.Percentage == 0 {
+		return 0
+	}
+
+	diskSize, err := getDiskSize(root)
+	if err != nil {
+		bklog.L.Warnf("failed to get disk size: %v", err)
+		return defaultCap
+	}
+	avail := diskSize * d.Percentage / 100
+	rounded := (avail/(1<<30) + 1) * 1e9 // round up
+	return rounded
+}