Add support for rebuilding on newer Ubuntu versions

[hugomonizdorego]

Request to update Customizer to support rebuilding and compatibility with the latest Ubuntu releases. Please investigate changes required for newer Ubuntu versions and update build scripts or dependencies as needed.

Expected outcome:

• Ensure Customizer can be rebuilt and run on recent Ubuntu distributions (such as 22.04, 24.04, etc.).
• Document any changes required for installation or usage on new Ubuntu versions.
• Update README or related documentation to reflect new support.

This feature request is important for users who rely on Customizer for modern systems.

[kamilion]

Four commits added to support python 3.10+ including 3.12's deprecations of imp and SafeConfigParser.
Makefile should handle 2.7 through 3.15 now.

Do you require additional commits to detect and support QT6, or is the existing QT4/QT5 support good enough for you?
With the license changes that QT6 imposes, and many applications and developers choosing to remain on QT5.15, and consistent distro support for it at the moment, there seems to be no great impetus.

If you run into a traceback, please report it.
Will close this issue by the end of 2025 if no further changes are required.

[kamilion]

This feature request is important for users who rely on Customizer for modern systems.

If you rely on customizer, a tool intended for deep invasive changes to the install media; you must be prepared to deal with changes made by Canonical to the install media. This takes a significant amount of insight and individual changes that are outside the scope of the customizer shell.

You are expected to have advanced skills to make proper use of this software. I am happy to improve customizer's shell to assist; but I am limited in my ability to test changes at the moment, nor am I receiving any compensation.

Also keep in mind; I've taken great pains to keep customizer operational even on python2.7 and QT4. It should still operate fine with versions as far back as ubuntu 12.04, for the people who have old systems and rely on projects like LXDE, LXQT, and XFCE.
Should anyone notice a failure in these old versions as a result of these updates; please let me know in another issue as soon as possible and I'll try to look into them. Patches/Merge Requests welcome. But I'm pretty sure I guessed at the logic correctly! 😅