Lift the upper limit for Python version

[soininen]

A function imported from the distutils module that has been removed from Python 3.12 had to be replaced, but otherwise, things seem to work fine.

Re spine-tools/Spine-Toolbox#2522

Checklist before merging

• [x] CHANGELOG.md has been updated
• [x] Unit tests have been added/updated accordingly
• [x] Code has been formatted by black
• [x] Unit tests pass

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 78.32%. Comparing base (a427173) to head (5bd4c45).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## 0.8-dev #381 +/- ## =========================================== + Coverage 78.30% 78.32% +0.02% =========================================== Files 75 75 Lines 9495 9504 +9 Branches 2011 2015 +4 =========================================== + Hits 7435 7444 +9 + Misses 1728 1727 -1 - Partials 332 333 +1 ```

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