fix: mark secureboot as supported for metal

Mark SecureBootSupported as true for MetalPlatform.

Signed-off-by: Edward Sammut Alessi <edward.sammutalessi@siderolabs.com>

Author: Slessi

pkg/machinery/platforms/platforms.go

@@ -139,6 +139,7 @@ func MetalPlatform() Platform {
 			BootMethodDiskImage,
 			BootMethodPXE,
 		},
+		SecureBootSupported: true,
 	}
 }