vendor: update buildkit to v0.18.0-rc2

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

vendor/github.com/moby/buildkit/util/testutil/workers/dockerd.go

@@ -50,6 +50,7 @@ func InitDockerdWorker() {
 		Unsupported: []string{
 			FeatureSecurityMode,
 			FeatureCNINetwork,
+			FeatureContentCheck,
 		},
 	})
 }

vendor/github.com/moby/buildkit/util/testutil/workers/features.go

@@ -30,6 +30,7 @@ const (
 	FeatureSecurityMode         = "security_mode"
 	FeatureSourceDateEpoch      = "source_date_epoch"
 	FeatureCNINetwork           = "cni_network"
+	FeatureContentCheck         = "content_check"
 )
 
 var features = map[string]struct{}{
@@ -56,6 +57,7 @@ var features = map[string]struct{}{
 	FeatureSecurityMode:         {},
 	FeatureSourceDateEpoch:      {},
 	FeatureCNINetwork:           {},
+	FeatureContentCheck:         {},
 }
 
 func CheckFeatureCompat(t *testing.T, sb integration.Sandbox, reason ...string) {

vendor/modules.txt

@@ -483,7 +483,7 @@ github.com/mitchellh/go-wordwrap
 github.com/mitchellh/hashstructure/v2
 # github.com/mitchellh/mapstructure v1.5.0
 ## explicit; go 1.14
-# github.com/moby/buildkit v0.18.0-rc1
+# github.com/moby/buildkit v0.18.0-rc2
 ## explicit; go 1.22.0
 github.com/moby/buildkit/api/services/control
 github.com/moby/buildkit/api/types