python-3.13 will drop "future". It seems most of the drivers which use it have conditional import, but tox still hard requires it. For support of the python-3.13 the tox "future" requirement will have to be dropped/relaxed. I tried to drop it in my fedora-41 python-3.13 test build and it seems it builds/tests OK

I just did this for six and started looking at future, but didn't finish. I'll bump that up in my list and try to get that done in the next few days. It should be fairly easy.

--Dan