Support Ubuntu new desktop installer.

[suikan4github]

Ubuntu 23.04 has been released with a new Desktop Instller. So, we need to consider what to do.

At this moment, the Ubuntu 23.04 situation is like this :

• The new Desktop Installer doesn't accept the partition under the device mapper.
• The ubiquity is unable to use.

So, there's no way to use Kaiten-Yaki right now. Once the Desktop Installer supports the partition under the device mapper, we will investigate further.