osbuild-worker: use the new ostree resolver API

vendor/github.com/osbuild/images/pkg/platform/bootmode.go

@@ -0,0 +1,25 @@
+package platform
+
+type BootMode uint64
+
+const (
+	BOOT_NONE BootMode = iota
+	BOOT_LEGACY
+	BOOT_UEFI
+	BOOT_HYBRID
+)
+
+func (m BootMode) String() string {
+	switch m {
+	case BOOT_NONE:
+		return "none"
+	case BOOT_LEGACY:
+		return "legacy"
+	case BOOT_UEFI:
+		return "uefi"
+	case BOOT_HYBRID:
+		return "hybrid"
+	default:
+		panic("invalid boot mode")
+	}
+}