[Merge] ~gunnarhj/ubuntu-release-upgrader:temp-font into ubuntu-release-upgrader:ubuntu/main

[Gunnar Hjalmarsson]

@Brian: If I unpack that file and do "cd 23.10.7" I see another tarball: mantic.tar.gz.

> and the run `sudo ./mantic` or something really close to that. ;-)

Not sure what you mean by that.

Anyway, I added one basic check as a prerequisite to run the code.
-- 
https://code.launchpad.net/~gunnarhj/ubuntu-release-upgrader/+git/ubuntu-release-upgrader/+merge/451815
Your team Ubuntu Core Development Team is requested to review the proposed merge of ~gunnarhj/ubuntu-release-upgrader:temp-font into ubuntu-release-upgrader:ubuntu/main.