GitHub Actions: Tox runs Python 3.14t tests on Python 3.12

Python 3.14 works as expected, but free-threaded Python 3.14t does not...

Python 4.14 tests run on: `platform linux -- Python 3.14.0, pytest-8.4.2, pluggy-1.6.0`
* https://github.com/kivy/python-for-android/actions/runs/18323516154/job/52182271732#step:5:42

Python 4.14t tests run on: `platform linux -- Python 3.12.3, pytest-8.4.2, pluggy-1.6.0`
* https://github.com/kivy/python-for-android/actions/runs/18323516154/job/52182271768#step:5:42

@kuzeyron @T-Dynamos Any hints on this problem?

Begin with the linked GitHub Actions run and compare the Python 3.14 and 3.14t job output, then inspect the repository's tox and workflow configuration. Done means the 3.14t job runs under Python 3.14t rather than Python 3.12 and the relevant CI tests pass.

Written by the indexing model from the issue text.