fix(orchestrator): skip UFFD write-protection test on ARM64

ARM64 kernels do not support UFFD write protection (UFFD_FEATURE_WP_ASYNC).
TestAsyncWriteProtection exercises this feature and fails on ARM64 CI.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

packages/orchestrator/pkg/sandbox/uffd/userfaultfd/async_wp_test.go

@@ -2,6 +2,7 @@ package userfaultfd
 
 import (
 	"os"
+	"runtime"
 	"testing"
 	"unsafe"
 
@@ -33,6 +34,9 @@ func TestAsyncWriteProtection(t *testing.T) {
 	if os.Geteuid() != 0 {
 		t.Skip("this test requires root privileges")
 	}
+	if runtime.GOARCH == "arm64" {
+		t.Skip("ARM64 kernels do not support UFFD write protection")
+	}
 
 	tests := []struct {
 		name          string