Actually use Python 2.7 in win-py27 job

[webknjaz]

No description provided.

[eduardo-rodrigues]

Thanks for spotting the typo. CC @henryiii.

[henryiii]

This is not a typo! cibuildwheel can build any version of Python from any version of Python, but it requires the host to have 3.6+ to run. So this is now broken. Notice the other jobs build all the other versions of Python but only have a single host 3.7 Python. This is not different because it only runs one job.

[webknjaz]

Oh, then it's better to add some code comment there...

[henryiii]

I did (in the revert PR). It's more obvious on the one above it, where all Python versions get built, I see that it could be a a little surprising on this one. I could leave off the number, I think GHA defaults to something more than 3.5, but I don't think they promise anything specific about the version you get by default, so I lock the version here. Maybe it would be cleaner/clearer though.

If a runner defaulted to 2.7 I'd throw a fit...

[henryiii]

It looks like setup-python's default is 3.x, which is the most recent Python supported. Since cibuildwheel is already being tested on 3.9-dev, I think we should be pretty safe in using the default even when it becomes 3.9 in the fall. I'll make a PR.

[henryiii]

The unknown Python version behavior they describe is if you don't call setup python, not if you call it with the default. :)