[Joltras]

Proposed changes

The readme states that Python 3.12 or newer is supported, but CI only ran the tests on Python 3.15, so the tests now run on 3.12, 3.13, 3.14 and 3.15 without cancelling the other versions when one fails. While testing the versions locally, the UI test helper turned out to only check whether the tkinter module exists, so on systems where the module is present but the Tk library is missing the whole test run aborted during collection. The helper now imports tkinter and skips the UI tests if that fails, while REQUIRE_UI_TESTS=1 still turns this into an error in CI.

Types of changes

What types of changes does your code introduce to this project?
Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)